Conveyor chain

ABSTRACT

A section of chain for conveying product along a material handling system includes a pin connecting a center link between two side links. The pin may be dialable or selectably positioned at the side links to control and adjust the wear surface of the pin relative to the chain links. The pin may have a rotationally non-symmetrical shaft portion to provide different wear surfaces that engage a center link of the section of chain. The different wear surfaces may be sized and shaped to accommodate wear at the wear surface of the center link. The shaft portion may include a rotationally non-symmetrical ball member or portion on the shaft portion to enhance flexibility of the section of chain. The pin may be dialed to the next position or wear surface in response to an output of a wear measurement device or system.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 10/969,825, filed Oct. 21, 2004, now U.S. Pat. No. 7,246,699,which is a continuation-in-part of U.S. patent application, Ser. No.10/383,825, filed Mar. 7, 2003 by Frost, now U.S. Pat. No. 6,991,094 ,which claims priority of U.S. provisional application, Ser. No.60/362,751, filed Mar. 8, 2002 by Frost; U.S. provisional applicationSer. No. 60/367,390, filed Mar. 25, 2002 by Frost; U.S. provisionalapplication, Ser. No. 60/381,518, filed May 17, 2002 by Frost; and U.S.provisional application, Ser. No. 60/425,577, filed Nov. 12, 2002 byFrost, which are all hereby incorporated herein by reference in theirentireties.

FIELD OF THE INVENTION

The present invention relates generally to chains for a conveying systemand, more particularly, to bolted or pinned chains which allow forpivotable movement between a center link and a pair of side links aboutan axis defined by a bolt or pin extending therethrough.

BACKGROUND OF THE INVENTION

Chains for power transmission or for material handling and processingsystems, such as, for example, chains which function to move a pluralityof trolleys or the like along a path in a processing plant, warehouse orthe like, flex as the chain travels along the desired path. As the chainis routed along the desired path, the chain may flex to make lateralturns and/or upward or downward curves along the path. As the chainflexes, the links of the chain may move relative to the pins or boltswhich define the joints of the chain. The relative movement of the linksand the pins or bolts leads to wear on the components and may eventuallylead to a failure of the links and/or the pins or bolts. The wear mayincrease if the friction between the pin and the links increases, suchas due to a roughened surface (such as by machining grooves, scratchesor the like) of one or more of the components and/or a lack oflubrication on the components.

In certain situations, the chains may have to negotiate an incline fromhorizontal which is approximately 45-60 degrees above or belowhorizontal. Such sharp inclines may result in binding of the chain linksas they flex or bend along the curve. It is known to provide an I-pinchain with a ball formed on the forged I-pin between the side links andthe center link of the chain. The I-pin may be forged with a ball orspherical shape at a center portion of the pin, such that the centerlink may be pivotable about the ball between the side links. The I-pinis fixed relative to the side link and center link of the chain, whichis commonly known as “rivetless chain.” The ball may provide foradditional flexibility in the chain, but still wears against the centerchain links as the chain links move relative to the pins.

Therefore, there is a need in the art for an improved chain thatovercomes the short comings of the prior art.

SUMMARY OF THE INVENTION

The present invention is intended to provide enhanced flexibility ofchain links and enhanced relative movement between the chain links andpins, while reducing or controlling wear on the chain or reducing orcontrolling the effects of wear on the chain components.

According to another aspect of the present invention, a pin forconnecting chain links together to define a section of chain forconveying product along a conveying system comprises opposite endportions for engaging at least one link of the section of chain, a shaftportion extending between the opposite end portions, and a sleeveportion around and at least partially along the shaft portion. Thesleeve portion is arranged on the shaft portion to engage another linkof the section of chain when the opposite end portions are engaged withthe at least one link of the section of chain. The sleeve portion ismovable relative to the shaft portion.

In one form, the sleeve portion comprises a generally spherical ortoroidal-shaped member, which may be generally centrally positionedalong the shaft portion. The sleeve portion may include a spacer portionat one or both ends of the toroidal-shaped member. The shaft portion ofthe pin may be generally cylindrical or may have a spherical or ball orrounded portion formed thereon. In another form, the shaft portion maycomprise a generally cylindrical shaft portion and the sleeve portionmay comprise a generally cylindrical sleeve portion.

The sleeve portion may comprise a polymeric material. The sleeve portionmay be molded onto the shaft portion of the pin, which may be an I-pinor bolted pin or the like, or the sleeve portion may be slid orremovably positioned over the shaft portion of a bolted pin or stud typepin when a fastener is removed from a fastener end of the pin.

Optionally, the sleeve portion may comprise a low coefficient offriction coating on an inner surface of the sleeve portion whichslidably engages the shaft portion, or the sleeve portion may comprise alow coefficient of friction coating on an outer surface of the sleeveportion which engages the other chain link.

According to another aspect of the present invention, a section of chainfor conveying product along a conveying system comprises a first chainlink, at least one second chain link having apertures through oppositeends thereof, and a pin. The second chain link comprises a recessed areasurrounding at least a portion of the aperture. The pin connects thefirst chain link to the second chain link via insertion of the pinthrough a respective one of the apertures in the second chain link andthrough an opening in the first chain link. The pin has at least onehead portion and a shaft portion, with the head portion defining amating surface. The recessed area rotatably receives the mating surfaceof the head portion of the pin. The mating surface is correspondinglyformed with the recessed area to facilitate relative rotationtherebetween. The mating surface engages the recessed area of the secondchain link and is rotatable relative to the second chain link as thesection of chain conveys product along the conveying system.

The aperture may comprise a slotted opening having a narrowed regionadjacent to the recessed area and a larger diameter region adjacent tothe narrowed region. The head portion of the pin is insertable throughthe larger diameter region and the shaft portion is slidable through thenarrowed region to the recessed area, whereby the mating surface of thehead portion engages the recessed area to retain the pin in theaperture.

According to another aspect of the present invention, a section of chainfor conveying product along a conveying system comprises at least twochain links having apertures through opposite ends thereof and a pinconnecting the chain links together via insertion of the pin through theapertures in the chain links. The pin comprises opposite end portionsand a shaft portion extending between the opposite end portions. Theshaft portion defines a wear surface which engages at least one of thechain links. The pin is selectably adjustable between at least threepositions relative to the chain links to adjust the wear surface of theshaft portion relative to the chain links. The pin is generallynon-rotatable relative to the chain links when in each of the at leastthree positions.

At least one of the end portions of the pin may define at least threeengaging portions for selectably engaging corresponding wall portions ofthe aperture of at least one of the chain links, whereby the pin isgenerally non-rotatable relative to the chain links by engagement of atleast some of the engaging portions with at least some of the wallportions when in each of the at least three positions.

According to another aspect of the present invention, a method ofadjusting a wear surface of a pin of a section of chain comprisesproviding a section of chain having at least two chain links havingapertures through opposite ends thereof and a pin connecting the chainlinks together via insertion of the pin through the apertures in thechain links. The pin comprises opposite end portions and a shaft portionextending between the opposite end portions. The shaft portion defines awear surface which engages at least one of the chain links. The pin isnon-rotatably positioned relative to the chain links in one of at leasttwo positions. The pin is generally non-rotatable relative to the chainlinks when in each of the at least two positions. The pin is selectablyrotated to a different one of the at least two positions relative to thechain links to adjust the wear surface of the shaft portion relative tothe chain links.

A degree of wear on the pin may be monitored and the pin may beselectably rotated to limit or control wear on wear surfaces of the pincorresponding to the at least two positions. The method may includemonitoring a degree of wear on a portion of the engaged wear surface ofthe pin and selectively rotating the pin to position a new wear surfaceat the chain link in response to the degree of wear. For example, themethod may include determining a degree of wear of the section of chainvia a wear measurement device, and may further include selectivelyrotating the pin in response to an output of the wear measurementdevice. The pin may be marked to indicate which of the at least twopositions have been selected and used.

According to another aspect of the present invention, a pin adapted forconnecting at least two chain links of a section of chain includes ashaft portion and at least one head portion at at least one end of saidshaft portion. The shaft portion is configured to engage at least one ofthe chain links. The shaft portion comprises a rotationallynon-symmetrical shaft portion and has at least two wear surfaces forengaging the chain link. The at least one head portion defines at leasttwo portions for selective engagement with a corresponding portion ofthe other of the chain links.

The shaft portion of the pin may include a ball member positionedthereon. The ball member may be rotationally non-symmetrical and maydefine the wear surfaces. The ball member may be integrally formed withthe shaft portion or may receive the shaft portion therethrough, and maybe removably positioned on the shaft portion.

According to yet another aspect of the present invention, a section ofchain for conveying product along a conveying system comprises at leasttwo chain links and a pin for connecting the chain links together. Atleast one of the chain links defines a pin engaging region. The pinengaging region defines a first wear surface. The pin has opposite endportions and a shaft portion and defines a second wear surface. At leastone of the first and second wear surfaces comprises a polymericmaterial.

At least one of the pin engaging regions and the pin has a lowcoefficient of friction coating thereon. The coating may comprise adiamond like coating at at least one of the first and second wearsurfaces.

According to another aspect of the present invention, a section of chainfor conveying product along a conveying system comprises at least twochain links and a pin for connecting the chain links together. At leastone of the chain links defines a pin engaging region. The pin engagingregion defines a first wear surface. The pin has opposite end portionsand a shaft portion and defines a second wear surface. At least one ofthe first and second wear surfaces comprises a replaceable wear surface,whereby the replaceable wear surface is removable from the at least onechain link and/or removable from the pin to facilitate replacement ofthe replaceable wear surface.

The replaceable wear surface may comprise a polymeric material. Thereplaceable wear surface may comprise a sleeve positionable around theshaft portion of the pin. The sleeve may comprise a toroidal-shapedmember. The replaceable wear surface may comprise an insert at an endportion of the at least one chain link, whereby the insert engages theshaft portion of the pin. The pin engaging regions and/or the pin mayhave a low coefficient of friction coating thereon, such as a TEFLON®coating or a diamond like coating or the like, at the first and/orsecond wear surfaces.

According to another aspect of the present invention, a pin forconnecting and retaining at least two chain links of a section of chaincomprises a shaft portion and a replaceable wear surface memberremovably positioned around at least a portion of the shaft portion. Thesection of chain is movable to convey product along a conveying system.The replaceable wear surface is removable from the pin to facilitatereplacement of the replaceable wear surface.

The pin may comprise at least one fastening portion at at least one endof the pin for receiving a fastener thereon to retain the pin at thechain links. The replaceable wear surface may be removable andreplaceable via sliding the replaceable wear surface off from and ontothe shaft portion at the fastening portion when the fastener is removedtherefrom. The replaceable wear surface may comprise a toroidal-shapedmember or a generally cylindrical member or the like. The replaceablewear surface may comprise a metallic or a polymeric material and may becoated with a low coefficient of friction material or coating.

According to yet another aspect of the present invention, an I-pin for achain includes opposite head portions and a shaft portion. A unitarypolymeric sleeve is movably positioned around at least a portion of theshaft portion of the I-pin. The polymeric sleeve may rotate or slidearound the shaft portion.

The sleeve may be molded onto the shaft portion and may be broken freeafter it has been molded and, thus, may be generally freely rotatableabout the shaft portion of the I-pin. The sleeve provides a unitarypolymeric component on the shaft portion of the I-pin for engagementwith the center link and/or side links of a chain. The sleeve may bemolded of a durable polymeric material.

Optionally, the shaft portion of the I-pin may have a smooth exteriorsurface to facilitate loosening or breaking free of the sleeve about theshaft portion. A low coefficient of friction surface or material may beprovided between the sleeve and the pin and/or between the sleeve andthe chain links.

In one form, the polymeric sleeve may be molded in a generally sphericalshape to provide a generally spherical or toroidal-shaped ball member onthe shaft portion of the pin. In another form, the shaft portion of thepin may include a ball member, such that the sleeve is molded over theball member of the pin. In another form, the sleeve may be a generallycylindrical sleeve molded over a generally cylindrical shaft portion ofthe pin.

According to another aspect of the present invention, a method forforming an I-pin includes forming a pin having a shaft portion andmolding a polymeric sleeve portion onto the shaft portion of the I-pin.The sleeve portion may be a generally cylindrical sleeve portion or maybe a generally spherically shaped ball member molded onto the shaftportion of the pin. The sleeve portion may be broken free from the shaftportion of the pin such that the sleeve portion is movably or slidablypositioned on the shaft portion.

Therefore, the present invention provides a pin member or pin which mayprovide enhanced flexibility and wear life to a section of chain. Thepin may have a movable sleeve portion around a shaft portion of the pinto reduce friction and wear on the pin and on the chain links of thesection of chain. The pin may include a ball member or toroidal-shapedmember at or on the shaft portion of the pin, and the center link mayinclude a concave engaging surface for engaging the ball member, toenhance flexibility of the section of chain. The present invention mayprovide a rotatable pin for rotating within the chain links as the chaintravels and bends along the conveying path. Optionally, the chain may beselectably rotated or dialed between two or more generally fixedorientations relative to the chain links to control the wear on the pinand enhance the life cycle of the pin. Optionally, the pin or one ormore of the chain links may have a wear surface which comprises apolymeric material, which may reduce friction between the pin and chainlinks. The polymeric wear surface may be a polymeric insert at an end ofthe center link or may be a polymeric sleeve portion molded orpositioned around the shaft portion of the pin. The pin may comprise anI-pin type of chain pin, a bolted type of chain pin or a double endedstud type of chain pin, and may include a generally spherical-shapedball member or toroidal-shaped member at the shaft portion to enhanceflexibility in the section of chain. Optionally, the pin and/or thechain link may have a replaceable wear surface member to facilitatereplacement of the wear surface or surfaces, without having to replacethe entire pin and/or chain link.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a ball and socket bolted chainor section of chain in accordance with the present invention, having adouble ended stud type pin;

FIG. 1A is a perspective view of a portion of a material handling systemincorporating a conveyor chain in accordance with the present invention;

FIG. 2 is a top plan view of the section of chain of FIG. 1;

FIG. 3 is a side elevation and partial sectional view of the section ofchain of FIGS. 1 and 2;

FIG. 4 is an exploded perspective view of another ball and socket boltedsection of chain in accordance with the present invention;

FIG. 5 is a top plan view of the section of chain of FIG. 4;

FIG. 6 is a side elevation and partial sectional view of the section ofchain of FIGS. 4 and 5;

FIG. 7 is a top plan view of another ball and socket bolted section ofchain in accordance with the present invention;

FIG. 8 is a side elevation and partial sectional view of the section ofchain of FIG. 7;

FIG. 9 is an exploded perspective view of another ball and socketsection of chain in accordance with the present invention;

FIG. 10 is a side elevation and partial sectional view of the ball andsocket section of chain of FIG. 9;

FIG. 11 is a perspective view of another ball and socket bolted sectionof chain in accordance with the present invention, with one of the sidelinks removed;

FIG. 12 is a top plan view of the section of chain of FIG. 11;

FIG. 13 is a side elevation and partial sectional view of the section ofchain of FIGS. 11 and 12, with both side links shown;

FIG. 14 is a top plan view of another bolted section of chain with thebolted pin being rotatable relative to the chain links;

FIG. 15 is a side elevation and partial sectional view of the section ofchain of FIG. 14;

FIG. 15A is a side elevation and partial sectional view similar to FIG.15, with a chamfered head and nut that are rotatably received withinrecesses on the respective side links;

FIG. 16 is a perspective view of a ball and socket I-pin section ofchain in accordance with the present invention with a pin rotatablyreceived through the chain links, with one of the side links removed toshow additional detail of the pin;

FIG. 17 is a top plan view of the section of chain of FIG. 16;

FIG. 18 is a side elevation and partial sectional view of the section ofchain of FIGS. 16 and 17, with both side links shown;

FIG. 18A is a side elevation and partial sectional view of anothersection of chain similar to that of FIGS. 16-18, but with chamferedfasteners at either end of a double ended stud pin;

FIG. 19 is a top plan view of another I-pin section of chain with theI-pin being rotatable relative to the chain links;

FIG. 20 is a side elevation and partial sectional view of the section ofchain of FIG. 19;

FIG. 21 is a perspective view of another ball and socket I-pin sectionof chain in accordance with the present invention, with the pin beingselectably non-rotatably positioned at the chain links, shown with oneof the side links removed to show additional detail of the pin;

FIG. 22 is a top plan view of the section of chain of FIG. 21;

FIG. 23 is a perspective view of another ball and socket I-pin sectionof chain with the pin being selectably non-rotatably positioned at thechain links, shown with one of the side links removed to show additionaldetail of the pin;

FIG. 24 is a top plan view of the section of chain of FIG. 23;

FIG. 25 is a side elevation and partial sectional view of the section ofchain of FIGS. 23 and 24, with both side links shown;

FIG. 26 is a top plan view of another section of chain similar to thesection of chain of FIGS. 23-25, with a pin having a generallycylindrical shaft portion;

FIG. 27 is a side elevation and partial sectional view of the section ofchain of FIG. 26;

FIG. 28 is a perspective view of another section of chain similar to thesections of chain of FIGS. 23-27, with a bolted-pin being non-rotatablypositioned at the section of chain, shown with one of the side linksremoved to show additional detail of the bolted pin;

FIG. 29 is a top plan view of the section of chain of FIG. 28;

FIG. 30 is a side elevation and partial sectional view of the section ofchain of FIGS. 28 and 29;

FIG. 31 is a top plan view of another section of chain similar to thesection of chain of FIGS. 28-30, with a bolted-pin having a generallycylindrical shaft portion;

FIG. 32 is a side elevation and partial sectional view of the section ofchain of FIG. 31;

FIG. 33 is an exploded perspective view of a ball and socket section ofchain in accordance with the present invention, with a ball membermolded around a shaft portion of a pin;

FIG. 34 is a side elevation and partial sectional view of the section ofchain of FIG. 33;

FIG. 35 is a side elevation and partial sectional view of another balland socket section of chain in accordance with the present invention;

FIG. 36 is a side elevation and partial sectional view of another balland socket section of chain in accordance with the present invention,with a sleeve molded around the shaft portion and ball member of thepin;

FIG. 37 is a side elevation and partial sectional view of a section ofchain in accordance with the present invention, with a generallycylindrical sleeve molded over a generally cylindrical shaft portion ofthe pin;

FIG. 38 is a perspective view of a center link and pin of anothersection of chain in accordance with the present invention, with aplastic insert at each end of the center link;

FIG. 39 is a side elevation and partial sectional view of anothersection of chain in accordance with the present invention, with aplastic insert at each end of the center link and a ball member formedon the shaft of the pin;

FIG. 40 is a side elevation and partial sectional view of anothersection of chain in accordance with the present invention, with arounded plastic insert at each end of the center link and a concave ornarrowed shaft of the pin;

FIG. 41 is a perspective view of a rotationally non-symmetrical pin inaccordance with the present invention;

FIG. 42 is a side elevation of the pin of FIG. 41;

FIG. 43 is a sectional view taken along the line A-A in FIG. 42;

FIG. 44 is another side elevation of the pin of FIG. 41;

FIG. 45 is a perspective view of a pin having a rotationallynon-symmetrical ball member in accordance with the present invention;

FIG. 46 is a side elevation of the pin of FIG. 45;

FIG. 47 is a sectional view taken along the line B-B in FIG. 46;

FIG. 48 is another side elevation of the pin of FIG. 45;

FIG. 49 is a chain section in accordance with the present invention;

FIG. 50 is a plan view of the chain section of FIG. 49;

FIG. 51 is a side elevation of the chain section of FIG. 49;

FIG. 52 is an end elevation of the chain section of FIG. 49;

FIG. 53 is a perspective view of a rotationally non-symmetrical pin ofthe chain section of FIGS. 49-53;

FIG. 54 is a side elevation of the pin of FIG. 53;

FIG. 55 is a sectional view taken along the line C-C in FIG. 54;

FIG. 56 is another side elevation of the pin of FIG. 53;

FIG. 57 is a chain section in accordance with the present invention;

FIG. 58 is a plan view of the chain section of FIG. 57;

FIG. 59 is a side elevation of the chain section of FIG. 57;

FIG. 60 is an end elevation of the chain section of FIG. 57;

FIG. 61 is a perspective view of a rotationally non-symmetrical pin ofthe chain section of FIGS. 57-60;

FIG. 62 is a side elevation of the pin of FIG. 61;

FIG. 63 is a sectional view taken along the line D-D in FIG. 62; and

FIG. 64 is another side elevation of the pin of FIG. 61.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depictedtherein, a chain or section of chain 10 for conveying product along aconveying system 11, such as for material handling or processing systemsor the like, includes a pair of side links 12 a, 12 b and a center link14 (FIGS. 1-3). The center link 14 is retained between the side links 12a, 12 b by a double ended stud or stud type pin 16, which extendsthrough a center region 14 a of center link 14 and through an opening 13in each side link 12 a, 12 b and is retained therein by a correspondingfastener or nut 18. Stud 16 includes a generally spherical ortoroidal-shaped ball member 20 positioned generally at a mid-point ormid-region of a shaft portion 16 a of stud 16. Chain 10 includesmultiple linkages connected together in a continuous loop 11 a about aconveying system 11 (FIG. 1A), as is known in the art. For ease ofdescription, only one section or set of linkages of the chain is shownand described herein, with the other linkages of the chain beingsubstantially identical.

Stud 16 includes center or shaft portion 16 a and a pair of oppositethreaded portions or fastener portions or ends 16 b. Threaded portions16 b are of a narrower diameter than shaft portion 16 a, such that theends of center portion 16 a provide an abutting surface 16 c against thefastener 18 as the fastener is tightened onto stud 16 or for abuttingagainst an inward side of the respective side link 12 a, 12 b, tomaintain the spacing between the side links when the chain is assembled.Stud 16 may comprise a metallic material, such as steel, stainless steelor iron or the like, similar to conventional studs or pins of chain formaterial handling systems and the like.

Ball member 20 may be integrally formed as part of stud 16 or may bepress-fit or otherwise secured on shaft portion 16 a to retain theposition of ball member 20 in the middle region of stud 16. However,ball member 20 may otherwise be loosely fit onto shaft portion 16 a ofstud 16 and allowed to slide along or rotate around stud 16, withoutaffecting the scope of the present invention. Ball member 20 maycomprise a metallic material or a plastic or polymeric material. Centerlink 14 is a generally oval shaped or elongated ring and includes aninner rounded or concave mating or engaging surface 14 b (FIGS. 2 and 3)at each end thereof for engaging and partially receiving ball member 20therein to retain center link 14 at ball member 20 as the chain is movedalong the conveying path.

Ball member 20 thus allows for pivotal movement of center link 14 viasliding engagement of concave surface 14 b along ball member 20. Thisprovides greater flexibility to bolted chain 10 and may allow boltedchain 10 to negotiate sharper vertical curves in the conveying pathwithout binding the links or joints of the chain. The ball member andcorrespondingly formed concave surface thus may distribute the loadsover a generally constant surface area, reducing or substantiallyeliminating the stress concentration that typically occur whenconventional chains articulate through vertical inclines and declines.The ball member and concave surface engagement may also function todistribute the loads between the chain links and stud or pin over agreater surface area than conventional chains. This decreases the wearon the bolt and chain links and may result in less maintenance and agreater life cycle for the chain.

Referring now to FIGS. 4-6, a chain or section of chain 110 includes apair of side links 112 a, 112 b and a center link 114. The center link114 is retained between corresponding ends of the side links 112 a, 112b by a bolt or bolted pin 116 extending through corresponding openings113 and through a center region 114 a of center link 114. Bolt 116includes a shaft portion 116 a, a threaded portion or end 116 b, whichthreadedly receives a nut 118 thereon to retain the chain linkstogether, and a head or head portion 116 c at an opposite end fromthreaded end 116 b. Bolt 116 further includes a generally spherical orgenerally toroidal-shaped ball member 120, which may slide onto shaftportion 116 a of bolt 116. Similar to center link 14, center link 114 isa generally elongated ring with a rounded or concave surface 114 b ateach end thereof for engaging and partially receiving ball member 120therein to maintain center link 114 on ball member 120.

Ball member 120 may be loosely fit along bolt 116 to ease assembly ofthe chain links and to allow the ball member 120, and thus the centerlink 114, to move between the side links as the chain links negotiatethrough the conveying path. Optionally, ball member 120 may snuglyreceive shaft portion 116 a or may be press fit onto shaft portion 116 ato retain ball member 120 in place on shaft member 116 a of bolt 116.Because ball member 120 defines a wear surface of bolt 116, ball member120 may be removably positioned on shaft portion 116 a to allow the ballmember and wear surface to be replaced without replacing the entirebolted pin, thereby reducing maintenance and replacement costs of thechain components.

Optionally, as shown in FIGS. 7 and 8, a chain or section of chain 110′includes side links 112 a, 112 b and a center link 114. The center link114 is retained between corresponding ends of the side links 112 a, 112b by a bolt or bolted pin 116′ extending through corresponding openings113 and through center region 114 a of center link 114. Bolt 116′includes a shaft portion 116 a′, a threaded portion or end 116 b′, whichthreadedly receives a nut 118′ thereon to retain the chain linkstogether, and a head or head portion 116 c′ at an opposite end fromthreaded end 116 b′. Bolt 116′ further includes a sleeve portion or aspacer-ball-spacer assembly or member or portion 119 (FIG. 8), which mayinclude a generally spherical or toroidal-shaped ball member or portion120′ and generally cylindrical spacers or sleeves 121 positioned atopposite ends of the ball member 120′. As discussed above, center link114 may be a generally elongated ring with a rounded or concave surface114 b at each end thereof for partially receiving ball member 120′therein to maintain center link 114 on ball member 120′.

Sleeve portion 119 may slide onto shaft portion 116 a′ of bolt 116′ ormay be molded thereon. Sleeve portion 119 may comprise a metallicmaterial, such as steel or the like, and may be treated or coated, suchas with a low coefficient of friction material or slick material, suchas a TEFLON® coating or material or a diamond like coating (DLC) orother suitable low friction material or the like; such that sleeveportion 119 provides a highly durable and slick wear surface or engagingsurface along shaft portion 116 a of bolt or pin 116. Optionally, sleeveportion 119 may comprise a polymeric material and may be slid onto ormolded onto shaft portion 116 a, which may comprise a metallic material.

Sleeve portion 119 may be loosely fit along bolt 116′ to ease theassembly of the chain and to allow the ball member 120′ and spacers orsleeves 121, and thus the center link 114, to move between the sidelinks as the chain links negotiate through the conveying path. Sleeveportion 119 may include a hollow spacer ring or sleeve 121 positionedaround and along the shaft 116 a′ at one or both sides of ball member120′ to maintain ball member 120′ generally at a center region of theshaft 116 a′ of pin 116′. The spacer-ball-spacer configuration orassembly may be formed as a unitary member (as shown in FIG. 8) or maybe separate components (one or two spacers and a ball member) slid ontothe shaft portion 116 a′, without affecting the scope of the presentinvention. By making the spacer-ball-spacer configuration a unitarystructure, assembly of the bolt and maintenance or replacement of thewear surface/ball member (if necessary) may be substantially simplified.

Such a spacer-ball-spacer configuration assists in maintaining the ballmember in the center region of the shaft of the pin, while allowing forgenerally free rotational movement of the ball member about the shaft.This helps to keep the ball member in alignment with the recess 114 b incenter link 114 as the chain bends and moves along its conveying path.The spacer-ball-spacer configuration also provides for low costreplacement of the wear portions of the pin, since thespacer-ball-spacer assembly may be replaced without replacing the entirepin. For example, the nut may be removed and the spacer-ball-spacerstructure (preferably a unitary structure) may be slid off of the boltand replaced, thereby providing a new wear surface (a new ball member)to the bolted pin, without replacing the entire bolted pin. This mayprovide significant cost savings, especially in applications where thepin may be formed of stainless steel or other expensive materials and,thus, may be costly to replace.

Referring now to FIGS. 9 and 10, a chain or section of chain 210includes a pair of side links 215, 212 and a center link 214. The centerlink 214 is retained between the side links 215, 212 by a threaded orbolted pin 216 which extends through a center region 214 a of centerlink 214 and through an opening 215 a in side link 215 and an opening213 in side link 212 and is retained therein and therethrough by acorresponding fastener or nut 218. Threaded pin 216 includes a generallyspherical or toroidal-shaped ball member 220 positioned generally atamid-point or mid-region of threaded pin 216. Similar to chain 10, chain210 includes multiple linkages connected together in a continuous loopabout a conveying system, as is known in the art. For ease ofdescription, only one set of linkages of the chain is shown anddescribed herein, with the other linkages being substantially identical.

Threaded pin 216 includes a center portion or shaft portion 216 a and athreaded portion 216 b at one end of the shaft portion 216 a and a heador head portion 216 c at the other end of the shaft 216 a. Threadedportion 216 b has a narrower diameter than center portion or shaft 216a, such that the end of shaft 216 a provides an abutting surface 216 dfor abutting against the fastener or nut 218 as the nut is tightenedonto threaded pin 216 or for abutting against an inward side of sidelink 212, to maintain the spacing between the side links when the chainis assembled.

As can be seen in FIGS. 9 and 10, head 216 c of threaded pin 216 is agenerally rectangular shaped head such that portions of the head 216 cextend laterally outward from the end of the shaft 216 a in oppositedirections. Side link 215 includes a pair of slotted openings 215 awhich may be sized to receive head 216 c therethrough when the head isrotated approximately 90 degrees from the orientation shown in FIG. 9,in order to facilitate assembly and disassembly of the chain links.Alternately, side link 215 may include circular apertures or passagewayssimilar to side link 212, because the threaded portion 216 b and shaft216 a may be inserted through such an aperture or opening to assemblethe section of chain. Side link 215 includes a recessed region or pocket215 b at each end for head 216 c of threaded pin 216 to rest when thesection of chain is assembled. The recessed region 21 5 b is defined bya raised end portion 215 c and raised inward portions 215 d which engagethe sides of the head 216 c to substantially preclude rotation of thepin relative to the side and center links.

Center link 214 may be substantially similar to center links 14 and 114,discussed above, and may comprise a generally oval shaped or elongatedring defining an opening 214 a and having an inner rounded or concavesurface 214 b at each end of the center link for partially receivingball member 220 therein to retain center link 214 at ball member 220 asthe chain is moved along the conveying path.

Ball member 220 may be slid loosely onto shaft 216 a of threaded pin 216and allowed to slide and rotate along shaft 216 a, or may be press fitonto or substantially fixed relative to shaft 216 a, without affectingthe scope of the present invention. Alternately, the threaded pin andball member may be forged or otherwise integrally formed as a singlemember, without affecting the scope of the present invention.

Similar to ball members 20 and 120 of chains 10 and 110, respectively,ball member 220 of chain 210 allows for pivotal movement of center link214 via sliding engagement of concave surface 214 b along ball member220. This provides greater flexibility to chain 210 and may allow thechain to negotiate sharper vertical curves in the conveying path withoutbinding the links or joints of the chain. Chain 210 thus provides a halfrivetless—half bolted pin which may negotiate sharper vertical turnsand/or negotiate turns about different axes. The ball member andcorrespondingly formed concave surface thus may distribute the loadsover a generally constant surface area, reducing or substantiallyeliminating the stress concentration that typically occur whenconventional bolted chains articulate through vertical inclines anddeclines. The ball member and concave surface engagement may alsofunction to distribute the loads between the chain links and bolt over agreater surface area than conventional bolted chains. This decreases thewear on the bolt and chain links and may result in less maintenance anda greater life cycle for the chain.

Although shown as having a generally rectangular shaped head, thethreaded pin of the present invention may alternately have a roundedhead (not shown in FIGS. 9 and 10) which may rest upon a generally flator recessed side link, thereby allowing the threaded pin to rotaterelative to the side and center links, without affecting the scope ofthe present invention.

Referring now to FIGS. 11-13, a chain or section of chain 310 includes apair of side links 315, 312 and a center link 314. The center link 314is retained between the side links 315, 312 by a threaded pin or boltedpin 316 which extends through a center region 314 a of center link 314and through an opening 315 a in side link 315 and an opening 313 in sidelink 312 and is retained therein and therethrough by a correspondingfastener or nut 318. Threaded pin 316 includes a generally spherical ortoroidal-shaped ball member 320 positioned generally at a mid-point ormid-region of a shaft portion 316 a of threaded pin 316. Similar tochain 10, chain 310 includes multiple linkages connected together in acontinuous loop about a conveying system, as is known in the art. Forease of description, only one section or set of linkages of the chain isshown and described herein, with the other sections or sets of linkagesbeing substantially identical.

Threaded pin 316 includes center portion or shaft portion 316 a, athreaded portion or end 316 b at one end of the shaft portion 316 a, anda head portion 316 c at the other end of the shaft portion 316 a.Threaded portion 316 b has a narrower diameter than shaft portion 316 a,such that the end of shaft portion 316 a provides an abutting surface316 d for abutting against the fastener or nut 318 as the fastener istightened onto threaded pin 316 or for abutting against an inward sideof side link 312, to maintain the spacing between the side links whenthe chain is assembled. Head portion 316 c may include a hex head or thelike to facilitate preventing rotation of the bolt while the fastener318 is being fastened thereto.

As can be seen in FIGS. 11-13, head 316 c of threaded pin 316 is agenerally circular-shaped head. Side link 315 includes a pair of slottedopenings 315 a which include a larger inward opening 315 b, which may besized to receive head 316 c therethrough, in order to facilitateassembly and disassembly of the chain links, and a smaller outwardopening 315 c, which is smaller than the diameter of head 316 c toretain head 316 c therein. The smaller opening 315 c defines a narrowedslotted region adjacent to larger opening 315 b, to allow shaft portion316 a to slide along the slotted region to position head portion 316 cat smaller outward opening 315 c, whereby head portion 316 c is retainedin the smaller opening 315 c, as discussed below. Alternately, side link315 may include circular apertures or passageways similar to side link312, because the threaded portion 316 b and shaft portion 316 a may beinserted through such an aperture or opening to assemble the section ofchain.

Side link 315 includes a recessed area or region or pocket 315 d at andat least partially around the smaller opening 315 c at each end for headportion 316 c of threaded pin 316 to rest when the chain is assembled.The lower portion or mating surface 316 d (FIG. 13) of head portion 316c is preferably curved or rounded, while the recessed region 315 d iscorrespondingly formed to provide generally uniform engagement andmating between the mating surface 316 d of head portion 316 c andrecessed region 315 d. The correspondingly formed mating surface andrecessed region facilitate substantially smooth rotation between the pin316 and the link 315, such that the bolted pin 316 may freely rotaterelative to side links 315, 312 and center link 314 as the chain travelsalong its conveying path.

Center link 314 may be substantially similar to the center linksdiscussed above, and may comprise a generally oval shaped or elongatedring defining an opening 314 a and having an inner rounded or concavesurface 314 b at each end thereof for partially receiving ball member320 therein to retain center link 314 at ball member 320 as the chain ismoved along the conveying path.

Similar to the ball members and chains discussed above, ball member 320of chain 310 allows for pivotal movement of center link 314 via slidingengagement of concave surface 314 b along ball member 320. This providesgreater flexibility to chain 310 and may allow the chain to negotiatesharper vertical curves in the conveying path without binding the linksor joints of the chain. Chain 310 thus provides a half rivetless—halfbolted pin which may negotiate sharper vertical turns and/or negotiateturns about different axes. The ball member and correspondingly formedconcave surface thus may distribute the loads over a generally constantsurface area, reducing or substantially eliminating the stressconcentration that typically occur when conventional bolted chainsarticulate through vertical inclines and declines. The ball member andconcave surface engagement may also function to distribute the loadsbetween the chain links and bolt over a greater surface area thanconventional bolted chains. This decreases the wear on the bolt andchain links and may result in less maintenance and a greater life cyclefor the chain.

Ball member 320 may be slid loosely onto shaft portion 316 a of threadedpin 316 and allowed to slide and rotate along shaft portion 316 a, ormay be press fit onto or substantially fixed relative to shaft portion316 a, without affecting the scope of the present invention.Alternately, the threaded pin and ball member may be forged or otherwiseintegrally formed as a single member, without affecting the scope of thepresent invention. Optionally, ball member 320 may be loosely slid ontoshaft portion 316 a, and may include a hollow spacer ring or sleeve(such as shown generally at 321 in FIG. 13) positioned along and aroundthe shaft portion 316 a at one or both sides of ball member 320 tomaintain ball member 320 generally at a center region of shaft portion316 a of pin 316. The spacer-ball-spacer configuration or assembly maybe formed as a unitary member or may be separate components (two spacersand a ball member) slid onto the shaft portion 316 a, without affectingthe scope of the present invention. By making the spacer-ball-spacerconfiguration a unitary structure, assembly of the bolt and maintenanceor replacement of the ball member (if necessary) may be substantiallysimplified.

As discussed above with respect to bolted pin 116′, such aspacer-ball-spacer configuration assists in maintaining the ball memberin the center region of the shaft of the pin, while allowing forgenerally free rotational movement of the ball member about the shaft.This helps to keep the ball member in alignment with the recess 314 b incenter link 314 as the chain bends and moves along its conveying path.The spacer-ball-spacer configuration also provides for low costreplacement of the wear portions of the pin, since thespacer-ball-spacer assembly may be replaced without replacing the entirepin. The nut may be removed and the spacer-ball-spacer structure(preferably a unitary structure) may be slid off of the bolt andreplaced, thereby providing a new wear surface (a new ball member) tothe bolted pin, without replacing the entire bolted pin. This mayprovide significant cost savings, especially in applications where thepin may be formed of stainless steel or other expensive materials and,thus, may be costly to replace.

Referring to FIGS. 14 and 15, a chain or section of chain 310′ includesa pair of side links 315, 312 and a center link 314′. The center link314′ is retained between the side links 315, 312 by a threaded pin 316′which extends through a center region 314 a′ of center link 314′ andthrough an opening 315 a in side link 315 and an opening 313 in sidelink 312 and is retained therein and therethrough by a correspondingfastener or nut 318. Threaded pin 316′ includes a generally cylindricalshaft portion 316 a′, while center link 314′ includes a generally flator curved, non-concave surface 314 b′ for engaging shaft portion 316 a′.Chain 310′ may be otherwise substantially similar to chain 310,discussed above, such that a detailed discussion will not be repeatedherein. Head portion 316 c′ may include a curved or rounded matingsurface 316 d′, while side link 315 may include a correspondingly formedmating surface 315 d at the smaller slotted opening 315 c, as discussedabove, to facilitate generally smooth rotation of pin 316′ relative tothe chain links. Optionally, threaded pin 316′ may include a generallycylindrical sleeve portion (not shown in FIGS. 14 and 15) formed orpositioned around shaft portion 316 a′, such as discussed above or asdiscussed below.

Optionally, and as shown in FIG. 15A, a chain or section of chain 310″includes a pair of side links 312 a, 312 b and a center link 314′. Thecenter link 314′ is retained between the side links 312 a, 312 b by athreaded pin 316″ which extends through center link 314′ and through anopening 313 a in side link 312 a and an opening 313 b in side link 312 band is retained therein and therethrough by a corresponding fastener ornut 318′. The head portion 316 c″ may include a curved or rounded matingsurface 316 d″ for engaging a correspondingly formed mating surface 313c of side link 312 a, while the nut or female fastener 318′ may includea similarly curved or rounded or chamfered mating surface 318 a′ forengaging a correspondingly formed mating surface 313 d of side link 312b to facilitate generally smooth rotation of pin 316″ relative to thechain links. The engaging or mating surfaces 316 d″ and 318 a′ of thehead and nut may be generally correspondingly formed to match therecesses in the side links, such that the side links may be generallyinterchangeable without adversely affecting the rotation of the pinrelative to the side links. The chamfers or curved mating surfaces maybe at the ends of otherwise conventional hex heads and nuts, or maycomprise generally curved circular base portions (such as shown at thehead of the pins in FIGS. 11-15) of the heads and nuts to enhancerotation of the pin and reduce wear on the side links.

In the illustrated embodiment, threaded pin 316″ includes a generallycylindrical shaft portion 316 a″, while center link 314′ includes agenerally flat, non-concave surface 314 b′ for engaging shaft portion316 a″. However, the shaft portion may be otherwise formed, and mayinclude a ball member or the like formed or positioned thereon, such asdescribed herein. In applications with such a ball member, the side link312 a may be replaced with a side link similar to side link 315 of FIGS.11-15 to ease assembly of the section of chain. Optionally, the threadedpin 316″ may include a generally cylindrical sleeve portion (not shownin FIG. 15A) formed or positioned around shaft portion 316 a″, such asalso discussed herein. Chain 310′ may be otherwise substantially similarto chain 310, discussed above, such that a detailed discussion will notbe repeated herein.

Additionally, it is further envisioned that a round headed pin may beprovided with a rounded head at each end of the pin and a ball member onthe shaft portion between the heads or head portions. The head portionsmay insert through enlarged, generally circular openings in the sidelinks and slide outwardly toward the ends of the side links to anarrowed opening. The narrowed opening substantially precludes thecircular heads from moving therethrough, and thus retains the side linksrelative to the center links and the pin. The side links may include arecessed area around the narrowed opening to receive the rounded headtherein to substantially preclude longitudinal movement of the pinrelative to the side link toward the enlarged opening in the side link.The pin is thus allowed to rotate relative to the side links and thecenter link, while allowing greater flexibility and reduced wear of thechain.

For example, and with reference to FIGS. 16-18, a chain or section ofchain 410 includes a pair of side links 412 a, 412 b and a center link414. The center link 414 is retained between the side links 412 a, 412 bby a pin 416 which extends through a center region 414 a of center link414 and through an opening 413 in each side link 412 a, 412 b. Openings413 include a larger, inward generally circular opening 413 a and asmaller, outer generally circular slot or opening 413 b. Each headportion 416 c of pin 416 is smaller than the larger opening 413 a andlarger than the smaller end opening 413 b in each side link 412 a, 412 band retains pin 416 to side links 412 a, 412 b and center link 414. Pin416 includes a generally spherical or toroidal-shaped ball member 420positioned generally at a mid-point or mid-region of a shaft portion 416b of pin 416. Center link 414 may be substantially similar to the centerlinks discussed above and may comprise a generally oval-shaped orelongated ring having an inner rounded or concave surface 414 b at eachend thereof for partially receiving ball member 420 therein to retaincenter link 414 at ball member 420 as the chain is moved along theconveying path. Similar to chain 10, chain 410 includes multiplelinkages connected together in a continuous loop about a conveyingsystem, as is known in the art. For ease of description, only onesection or set of linkages of the chain is shown and described herein,with the other sections or sets of linkages being substantiallyidentical.

Pin 416 includes center portion or shaft portion 416 a and a headportion 416 c at each end of the shaft portion 416 a. Head portions 416c are generally circular and include an angled or curved undersideportion or mating surface 416 d (FIG. 18) which extends generallyradially outward from each end of the shaft portion 416 a such that headportion 416 c has a larger diameter than shaft portion 416 a.

As can be seen in FIGS. 16 and 17, each side link 412 a, 412 b includesa pair of slotted openings 413 which may be sized to receive head 416 cthrough the larger inward opening 413 a, in order to facilitate assemblyand disassembly of the chain. Once inserted through openings 413 a, pin416 and head portion 416 c may be moved outwardly until shaft portion416 a is within outer slot or opening 413 b. Head portion 416 c then mayrest at least partially within a curved recessed portion 413 c at outeropening 413 b, such that pin 416 and side links 412 a, 412 b and centerlink 414 are generally secured together. The curved recessed portion orregion 413 c is generally correspondingly formed with the mating surface416 d of head portion 416 c to facilitate generally uniform engagementand generally smooth rotation between the head portion of the pin andthe side links. Because the recessed portion 413 c and mating surface416 d of head portion 416 c are generally circular and arecorrespondingly formed, pin 416 is allowed to rotate relative to sidelinks 412 a, 412 b as the chain moves along its conveying path, in orderto substantially evenly distribute wear on the pin 416 and, thus, toextend the life cycle of the pin 416.

Similar to the other ball members discussed above, ball member 420 ofchain 410 allows for pivotal movement of center link 414 via slidingengagement of concave surface 414 b along ball member 420. This providesgreater flexibility to chain 410 and may allow the chain to negotiatesharper vertical curves in the conveying path without binding the linksor joints of the chain. Chain 410 thus provides a pin which maynegotiate sharper vertical turns and/or negotiate turns about differentaxes. The ball member and correspondingly formed concave surface thusmay distribute the loads over a generally constant surface area,reducing or substantially eliminating the stress concentration thattypically occur when conventional chains articulate through verticalinclines- and declines. The ball member and concave surface engagementmay also function to distribute the loads between the chain links andpin over a greater surface area than conventional chains. This decreasesthe wear on the bolt and chain links and may result in less maintenanceand a greater life cycle for the chain.

Optionally, and with reference to FIG. 18A, the pin 416′0 may includethreaded ends 416 b′ at opposite ends of the shaft portion 416 a′ andball member 420′. The threaded ends may be inserted through openings413′ in side links 412 a′, 412 b′ and retained therein via femalefasteners or nuts 418′. Similar to nut 318′, discussed above, nuts 418′may include a chamfered or curved or rounded mating surface 418 a′ forengaging a generally correspondingly curved or rounded recess 413 a′around opening 413′ of side link 412 a′, 412 b′. The correspondinglyformed surfaces allow for substantially smooth rotation of the pinrelative to the side links. The pin 416′ thus provides a rotatablebolted style pin with a ball member on the shaft portion of the pin,which may be readily assembled to the side and center links of a sectionof chain 410′.

Referring now to FIGS. 19 and 20, a chain or section of chain 410″includes a pair of side links 412 a, 412 b and a center link 414′. Thecenter link 414′ is retained between the side links 412 a, 412 b by arotatable pin 416″ which extends through a center region 414 a′ ofcenter link 414′ and through an opening 413 in each side link 412 a, 412b. Pin 416″ includes a generally cylindrical shaft portion 416 a″, whilecenter link 414′ includes a generally flat or non-concave surface 414 b′for engaging shaft portion 416 a″. Both head portions 416 c″ of pin 416″comprise a generally rounded and generally circular mating surface 416d″, while side links 412 a, 412 b include a correspondingly formedrecessed area or region or engaging surface 413 c for engaging matingsurfaces 416 d″ to facilitate generally smooth rotation between pin 416″and side links 412 a, 412 b. Chain 410″ may be otherwise substantiallysimilar to chain 410, discussed above, such that a detailed discussionwill not be repeated herein. Optionally, pin 416″ may include agenerally cylindrical sleeve portion (not shown in FIGS. 19 and 20)formed or positioned around shaft portion 416 a″, such as discussedabove or as discussed below.

It is further envisioned that a head portion of a pin of a section ofchain may be non-circular shaped and the recessed portion of at leastone of the side links may be correspondingly non-circular shaped, suchthat the head portion, and thus the pin, may be non-rotatably securedrelative to the side link. For example, the head portion and a recessedregion of a side link may be formed with two or more sides to providefor non-rotational engagement between the head and the recessed region,while allowing the head and bolt or pin to be manually rotated to adjustor change the wear surface engagement of the shaft and ball member withthe center link. For example, the pin or bolt portion (shaft and head)of a bolted pin may be ratcheted or rotated sixty degrees or ninetydegrees or some other amount (depending on the number of sides of thehead and the recessed region) to provide a new wear surface of the shaftand ball member (the portion that engages the center link and wears asthe links bend and turn relative to one another). The adjustable ordialable pin design of the present invention thus may provide for asignificant increase in the life cycle of the pin, because the ballmember (or spacer-ball-spacer assembly) may be replaced as needed,and/or the pin may be selectably rotated to provide a new wear surfaceas needed, which may substantially extend the overall life of the pin orbolted pin.

Each wear surface may span or cover approximately sixty or ninety or onehundred twenty degrees or the like about the pin, whereby the pin may berotated that amount as necessary to provide six or four or threedifferent wear surfaces or wear surface portions about the pin and,thus, to facilitate control of the amount of wear or amount of time ofwear on each wear surface portion. This may be especially useful inapplications where the chain is an exact pitch design (the chain lengthis specified with a small tolerance range), and excessive wear in one ormore of the pins may affect the pitch, which may cause the chain to bindor chains to bind (if two such chains are running alongside one anotherwith something connected or cradled between them) or may otherwiseadversely affect the chain or conveyor. The pins of such a chain maythen be dialed or rotated to provide a new wear surface for each pin,thereby effectively resetting the pins to their original tolerances andthus resetting the chain to its initial specified length. For example,each pin may be dialed to a second position or a third position or anyother position to move a fresh wear surface to the wear position. Insome cases, only a first pin or set of pins may need to be reset toprovide an appropriate adjustment. Optionally, the degree of wear on thepin or shaft portion (or wear surface) may be monitored or determined,and the pin may be selectably rotated to limit wear on the wear surfaceof the pin. It is further envisioned that each station or lobe on thehead portion of the pin may be marked or numbered to indicate whichportion or portions of the wear surface have already been selected orused. The shaft of the pin may define at least one wear surface, and maydefine two or more distinct wear surfaces, such as discussed below withrespect to FIGS. 41-64.

For example, and with reference to FIGS. 21 and 22, a head portion 516 cof a pin 516 and openings 513 b of side links 512 may be non-circular,such that pin 516 is non-rotatably positioned at and through side links512 of a chain or section of chain 510. For example, the head portion516 c may be lobed or non-circular shaped with three or more sides orportions 516 e (such as the three curved and generally equal-sized sidesshown in FIGS. 21 and 22), with the recessed area 51 3 c correspondinglyshaped to receive the head portion, such that the mating surfaces of thehead portion 516 c within the correspondingly formed recessed area orimpression 513 c in the side link 512 substantially precludes rotationof the pin 516 relative to the side links 512. For example, one or moreof the side portions of the head portion may engage a corresponding oneor more of the sidewalls of the side link at the aperture tosubstantially preclude rotation of the pin relative to the side links.The wear surface of the shaft portion 516 a and/or ball member 520 thusmay be generally fixed relative to the side links 512 by substantiallyfixing head 516 c within recess 513 c, such that only a portion of theshaft and/or ball member will contact and wear against the concavesurface 514 b of the center link 514 as the chain travels along itsconveying path.

The pin may be generally non-rotatable relative to the chain links whenin each of the positions (such as in each of the three positions in theillustrated embodiment of FIGS. 21 and 22, or such as in each of the sixpositions in the illustrated embodiment of FIGS. 23-25, discussed below,or such as in any other number of positions suitable for such anarrangement), and may be selectably adjustable between the positions toadjust the wear surface of the shaft portion of the pin relative to thechain links, thereby providing selective engagement of a portion orportions of the wear surface with the chain links. Such an arrangementallows for controlling the wear and life cycle of the pin by wearing aparticular wear surface of the pin at a time, and allows for controlledor manual or selective rotation from one wear surface of the pin to thenext wear surface of the pin. The pin and side link arrangement of thepresent invention thus provides a dialable pin, which may be manuallyand selectably dialed or rotated to provide a new wear surface againstthe side link after the first wear surface has been sufficiently worn.Such a configuration facilitates control of the amount of time each wearsurface or wear surface portion of the pin is in use.

Optionally, and with reference to FIGS. 23-25, a head portion 516 c′ ofa pin 516′ and openings 513 b′ of side links 512′ may be non-circular,such that pin 516′ is non-rotatably positioned at and through side links512′ of a chain or section of chain 510′. As shown in FIGS. 23-25, thehead portion 516 c′ may be generally hex-shaped, with the recessed area513 c′ being correspondingly shaped to receive the head portion, suchthat the mating of the head portion 516 c′ within the correspondinglyformed recessed area or impression 513 c′ in the side link 512′substantially precludes rotation of the pin 516′ relative to the sidelinks 512′ in six positions. The wear surface of the shaft portion 516a′ and/or ball member 520′ may be generally fixed relative to the sidelinks 512′ by substantially fixing head 516 c′ within recess 513 c′,such that only a portion of the shaft and/or ball member will contactand wear against the concave surface 514 b of the center link 514 as thechain travels along its conveying path. The wear surface may then beadjusted or dialed to a new surface by rotating the pin 516′ to a nextorientation relative to the recesses 513 c′ in the side links 512′, asdiscussed above.

Optionally, and with reference to FIGS. 26 and 27, a chain or section ofchain 510″ may include a pin 516″, which may comprise shaped or lobed orhex-shaped head portions 516 c″ at opposite ends of a generallycylindrical shaft portion 516 b″. The center link 514″ includes agenerally flat or curved, non-concave surface 514 b″ for engaging theshaft portion 516 b″. Pin 516″ and side links 512′ may be otherwisesubstantially similar to pin 516′ discussed above, such that a detaileddiscussion will not be repeated herein.

Optionally, and with reference to FIGS. 28-30, a chain or section ofchain 610 may include a threaded pin or bolt 616, which may comprise ashaft portion 616 a and a shaped or lobed or hex-shaped head portion 616c at one end and a threaded portion 616 b at an opposite end forreceiving a nut or threaded fastener or the like 618 (FIG. 30). Headportion 616 c may be received in a correspondingly formed or shapedrecess 613 c in one side link 612 a, while a generally cylindrical shaftportion 616 a and/or threaded end portion 616 b may extend through anopening 613 in the other side link 612 b of chain 610. The center link614 includes a concave inner surface 614 b for engaging a ball member620 positioned along shaft portion 616 a of pin 616. Ball member 620 maybe formed as part of shaft portion 616 a or may be slid onto or formedor molded onto shaft portion 616 a, and pin 616 may include a generallycylindrical sleeve portion over and along shaft portion 616 a, such asany of the types of sleeves discussed above or below. Chain 610 may beotherwise substantially similar to chain 510, discussed above, such thata detailed discussion will not be repeated herein.

Optionally, and with reference to FIGS. 31 and 32, a chain or section ofchain 610′ may include a threaded pin or bolt 616′, which may comprise ashaft portion 616 a′ and a non-circular shaped or lobed or hex-shapedhead portion 616 c′ at one end and a threaded portion 616 b′ at anopposite end for receiving a nut or threaded fastener or the like 618.Head portion 616 c′ may be received in a correspondingly formed orshaped recess 613 c in one side link 612 a, while a generallycylindrical shaft portion 616 a′ and/or threaded end portion 616 b′ mayextend through an opening 613 in the other side link 612 b of chain610′. The center link 614′ may include a generally flat or non-concaveinner surface 614 b′ for engaging shaft portion 616 a′ of pin 616′.Optionally, pin 616′ may include a generally cylindrical sleeve portionover and along shaft portion 616 a′, such as the types of sleeveportions discussed above or below. Chain 610′ may be otherwisesubstantially similar to chain 610, discussed above, such that adetailed discussion will not be repeated herein.

It is further envisioned that the shaft portions of the pins or studs orbolted pins may provide different or distinct wear surfaces when theyare rotated or dialed to the next setting, in order to accommodatewearing at the wear surface of the center links or elsewhere in thechain links. The shaft portion thus may provide two or more differentwear surfaces, with each particular wear surface corresponding to adialable setting of the pin and head relative to the chain links. Forexample, each subsequent wear surface may be larger than (or have alarger radius relative to the center axis of the pin) the previous wearsurface, in order to take up or account for any loss in dimensions ofthe wear surface of the center link. The shaft portion of the pin thusmay be rotationally non-symmetrical or non-uniform, such that differentwear surfaces may be provided by rotating or dialing the pin to the nextsetting. The wear surfaces may have different radii and may extenddifferent amounts outward from the center axis of the shaft portion,such that the pin may effectively be a different size or radius byrotating or dialing the pin to the next setting, whereby an effectivesize or diameter of the shaft may be larger to replace a smallereffective size shaft, in order to accommodate the wear or erosion ordeterioration of the wear surface of the center link. Each wear surfaceof the pin may correspond with a respective lobe or portion of the headportion of the pin, such that when a particular lobe is positioned in aparticular part of the recess in the side link, the respective wearsurface of the pin is generally aligned with the wear surface of thecenter link.

For example, and with reference to FIGS. 41-44, a chain or section ofmay include a pin 1016, which may comprise a shaft portion 1016 a andopposite head portions 1016 b. Pin 1016 a may comprise an I-pin type ofpin, and the head portions 1016 b may be received in a correspondinglyformed or shaped recesses in respective side links of the section ofchain (such as the head portions of the pins of FIGS. 9, 10 and 21-32,discussed above), while the shaft portion 1016 a includes at least onewear surface 1017 that engages a center link of the section of chain.The section of chain is not shown in FIGS. 41-44, but may be otherwisesubstantially similar to the chains or sections of chain describedherein such that a detailed discussion will not be repeated herein.Shaft portion 1016 a is rotationally non-symmetrical or non-uniform,such that the wear surface 1017 of the shaft portion 1016 a comprisestwo distinct wear surfaces 1017 a, 1017 b, which are selectivelypositioned to engage the end portion of the center link. The differentwear surfaces 1017 a, 1017 b provide different surfaces at the centerlink when the pin is rotated or flipped 180 degrees.

For example, the pin 1016 may initially be positioned at the chain linkssuch that wear surface 1017 a engages the center link. Wear surface 1017a provides a smaller radius surface or radius of curvature than wearsurface 1017 b (which protrudes further outward from a center axis 1016c of pin 1016 than wear surface 1017 a). After the wear surface 1017 ahas worn (and after the wear surface of the center link has also worn),the pin may be rotated 180 degrees such that wear surface 1017 b ispositioned to engage the center link. The larger radius wear surface1017 b accommodates any wear that may occur to the surface of the centerlink to provide similar overall dimensions of the chain links ascompared to the initial dimensions (when the first wear surface 1017 awas initially positioned to engage the wear surface of the center link).The pin may be an I-pin as shown, or may be any other type of pin orthreaded stud or bolt or the like or may have multiple lobes thatcorrespond to the different wear surfaces, such as discussed below withrespect to FIGS. 49-64, without affecting the scope of the presentinvention.

Optionally, and with reference to FIGS. 45-48, the pin 1016′ maycomprise an I-pin with a ball member 1020 positioned along the shaftportion 1016 a′. Ball member 1020 is rotationally non-symmetrical ornon-uniform and comprises two wear surfaces 1017 a′, 1017 b′, which areselectively positioned to engage a wear surface or end portion of thecenter link of the section of chain. Pin 1016′ and the chain section maybe otherwise substantially similar to the pins and chains describedherein such that a detailed discussion will not be repeated herein. Theball member may be integrally or unitarily formed as part of the shaftportion or may be fixedly or movably positioned on the shaft portionand/or may be molded onto the shaft portion or may receive the shaftportion therethrough, without affecting the scope of the presentinvention. Although shown and described as having a ball member with twowear surfaces, the ball member of the pin may provide three or more wearsurfaces (such as described below with respect to pins 1116 and 1216),without affecting the scope of the present invention. The pin may be anI-pin as shown or may be any other type of pin or threaded stud or thelike or may have multiple lobes that correspond to the different wearsurfaces, such as discussed below with respect to FIGS. 49-64, withoutaffecting the scope of the present invention.

Optionally, and with reference to FIGS. 49-56, a chain or section of1110 may include a pin or bolt 1116, which may comprise a shaft portion1116 a and a head portion 1116 b at one end and a threaded portion 1116c at an opposite end for receiving a nut or threaded fastener or thelike 1118. Head portion 1116 b may be received in a correspondinglyformed or shaped recess 1113 a in one side link 1112 a, while shaftportion 1116 a and/or threaded end portion 1116 c may extend through anopening 1113 b in the other side link 1112 b of chain 1110. Head portion1116 b may be selectively received in the correspondingly formed orshaped recesses 1113 a in side link 1112 a, while the shaft portion 1116a may engage a wear surface of a center link (not shown). Shaft portion1116 a is rotationally non-symmetrical and comprises three distinct wearsurfaces 1117 a, 1117 b, 1117 c, which engage the end portion or wearsurface of the center link. Each wear surface 1117 a, 1117 b, 1117 ccorresponds to a different lobe 1116 b′, 1116 b″, 1116 b′″ of headportion 1116 b to provide different surfaces at the center link when thepin is rotated approximately 120 degrees.

For example, the pin 1116 may be initially positioned at the chain linkssuch that wear surface 1117 a engages the center link. Wear surface 1117a provides a smaller diameter surface than wear surface 1117 b (whichprotrudes radially further from a center axis 1116 d of pin 1116 thanthe first or smaller wear surface 1117 a), which in turn provides asmaller diameter surface than wear surface 1117 c (which protrudesradially further from center axis 1116 d than second wear surface 1117b). After the first wear surface 1117 a has worn, the pin may be rotated120 degrees such that lobe 1116 b″ (which may have a number “2” or otherindicia printed or formed thereon to indicate the order of the wearsurfaces of the pin) is at the end position of the link to align wearsurface 1117 b with the wear surface of the center link, and the pin maybe further rotated or dialed to the third setting in a similar manner,as desired. The larger wear surface of the second or third settingaccommodates any wear or erosion or deterioration or degradation thatmay occur to the surface of the center link during use of the chain withthe pin at the previous setting, in order to provide similar overalldimensions of the chain links as compared to the initial dimensions.Chain 1110 may be otherwise substantially similar to the chainsdescribed herein such that a detailed discussion will not be repeatedherein.

Optionally, and with reference to FIGS. 57-64, a chain or section of1210 may include a pin or bolt 1216, which may comprise a shaft portion1216 a and a lobed head portion 1216 b at one end and a head portion orend portion 1216 c at an opposite end. Head portion 1216 b may bereceived in a correspondingly formed or shaped recess 1213 a in one sidelink 1212 a, while shaft portion 1216 a and/or end portion 1216 c mayextend through an opening 1213 b in the other side link 1212 b of chain1210. Head portion 1216 b may be selectively received in thecorrespondingly formed or shaped recesses 1213 a in side link 1212 a,while the shaft portion 1216 a may thus selectively engage a wearsurface of a center link (not shown). As can be seen in FIGS. 57 and 58,the recess 1213 a in side link 1212 a has slots or channels or recessesformed to receive the respective lobes of the head portion 1216 b.Preferably, the side link has an opening or aperture 1213 a′ next to oropposite to the end recess 1213 a″ that extends through the side link1212 a, such that the lobe of the pin may slide along and through theopening to facilitate insertion of the head portion into the opening inthe side link to facilitate assembly of the section of chain.

In the illustrated embodiment, the opposite head portion 1216 ccomprises a two-lobed head portion having lobes extending radiallyoutwardly from a longitudinal axis of the pin in generally oppositedirections from one another (such as is typically done at both ends ofknown I-pins and the like). Because head or end portion 1216 c is only atwo-lobed head, head portion 1216 c may be readily inserted through theopenings 1213 a′, 1213 b in the side links and through the opening inthe center link to assemble the section of chain. The pin 1216 thusprovides an adjustable or dialable rivetless or non-bolted style pinthat can be readily assembled to the chain links of a section of chain.

Optionally, the side link 1212 b may include a recess or notch at theend of the opening 1213 b and opposite to the end recess to providesupport for one of the lobes of the head portion 1216 c when it isoriented with the lobes extending generally longitudinally along theside link. The lobes of the head portion 1216 c thus may be fullyengaged with and supported by the recesses at the side link 1212 b ineach of the four (or three or more) orientations that the pin may be setat when the pin and links are assembled together. Optionally, it isenvisioned that the opening in one or both of the side links may beangled to allow for insertion of the two-lobed head portion 1216 c,while the surfaces of the recesses limit withdrawal of the pin from theside link when the pin is in any of the four positions of the lobed pinrelative to the side links. For example, the side link 1212 b mayinclude an elongated opening that is oriented at about a forty-fivedegree angle relative to the longitudinal axis of the side link so thatthe pin head portion 1216 c may insert through the opening and then maybe rotated forty-five degrees in either direction to align the lobeswith an engaging surface or recess of the side link while positioningthe pin at a desired initial orientation relative to the chain links.Optionally, it is further envisioned that the lobes of the opposite headportion 1216 c may be oriented at an angle relative to the lobes of thefirst head portion 1216 b and then may engage recesses in the side link1212 b that are oriented at angles relative to the recesses at the otherlink 1212 a when the pins and links are assembled together. Althoughshown on a pin having a four-lobed head portion, it is envisioned thatthe two-lobed head portion may be provided on a pin having a three lobedhead portion or other types of dialable head portions, without affectingthe scope of the present invention.

Shaft portion 1216 a of pin 1216 is rotationally non-symmetrical andcomprises four wear surfaces 1217 a, 1217 b, 1217 c, 1217 d, which areselectively positioned to engage the end portion or wear surface of thecenter link. Each wear surface 1217 a, 1217 b, 1217 c, 1217 dcorresponds to a different lobe 1216 a′, 1216 a″, 1216 a′, 1216 a′″ ofhead portion 1216 a to provide different surfaces at the center linkwhen the pin is rotated approximately 90 degrees. For example, the pin1216 may initially be positioned at the chain links such that wearsurface 1217 a engages the center link (with lobe 1216 a′ positioned atrecess 1213 a″ of side link 1212 a), and the pin may be rotated 90degrees (to position lobe 1216 a″ at recess 1213 a″) after the pin andchain link have worn a sufficient or specified amount, and furtherrotated as farther wear occurs. The different wear surfaces provideincreasing effective diameters of the shaft of the pin, in order toaccommodate wear or erosion or deterioration or degradation of the wearsurface of the center link during use of the pin and chain, as describedabove with reference to pins 1016, 1116. Chain 1210 may be otherwisesubstantially similar to the chains described herein such that adetailed discussion will not be repeated herein.

In the illustrated embodiments, the pin may have an I-pin type head atits end opposite from the multiple lobed head or may have a threaded endfor threadedly receiving a nut or fastener or the like to retain the pinat the side link, without affecting the scope of the present invention.As discussed above, the I-pin type head or two-lobed head allows therivetless or non-bolted pin to be readily assembled to the chain linksof the section of chain. However, it is envisioned that other head orend configurations, such as a three or four lobed head similar to themulti-lobed or dialable head portion of the pin may be incorporated atthe opposite end of the pin or bolt or stud, without affecting the scopeof the present invention. Also, although shown as having generallystraight shaft portions, the shaft portion of the multiple wear surfacepin may include a ball member that is rotationally non-symmetrical, suchas described above, without affecting the scope of the presentinvention.

The dialable pin of the present invention thus may be rotated or dialedto the next position when the degree of wear on the engaged wear surface(the wear surface of the pin that is engaged with the wear surface ofthe center link) and/or the center link wear surface approaches orreaches approximately a predetermined amount. The degree of wear in thechain may be determined by detecting various points or locations alongthe chain as the chain is driven or moved along its path, in order todetermine or estimate the degree of wear in the chain links or pins ofthe section or sections of chain between the detected points orlocations. For example, a chain measurement or wear measurement deviceor system may detect points along a chain and calculate the distancebetween the points (such as by determining the distance between thepoints based on the speed of the chain and the time that elapses betweenthe detections). As the distance between the points changes, the systemmay determine the wear in the pins or links for that chain section. Thechain wear measurement device or system may detect any desired orappropriate or suitable location along the chain, or may detect the endsof the pins, such as at an extension at an end of one or more pins, suchas is accomplished by the chain wear measurement device described inU.S. patent application, Ser. No. 10/356,063, filed Jan. 31, 2003 byFrost for WEAR MEASUREMENT DEVICE, and published Jul. 31, 2003 as U.S.publication No. US-2003-0140709-A1 , now U.S. Pat. No. 6,862,939, whichis hereby incorporated herein by reference. For example, a wearmeasurement system or device may include a sensor positioned along aconveying path of a conveyor system, where the sensor is operable todetect at least one of the pins (or other points or locations) of thesection of chain as the chain is conveyed along the conveying path. Thesensor generates a signal indicative of the detection of the pin (suchas a detection of an extension from an end of one or more of the pins ofthe chain) or other location or locations along the chain. The pin orpins of the section of chain may be dialed or rotated to the nextposition to align the next or larger wear surface with the center linkwear surface in response to an output of the wear measurement device orsystem, such as an output that is indicative of a particular degree ofwear in a section or length of chain (as calculated or estimated inresponse to the detection of the ends of the pins or of other locationsalong the section of chain).

By providing a larger radius wear surface (or a new wear surface thatprotrudes further from a center axis of the pin from the previous wearsurface and thus provides a larger effective diameter of the shaft ofthe pin) at the next selected or dialed wear surface of the pin, thedegree of wear in the pin and links may be taken up or replaced with thelarger wear surface when the pin is dialed or rotated to the next wearsurface. The rotationally non-symmetrical or non-uniform wear surfacesof the pin may be designed to provide a particular increase in theeffective diameter of the pin for each wear surface, such that the pinmay be dialed to the next wear surface when a particular degree of wear(that may generally or substantially correspond with the particularincrease in the wear surface of the pin) in the chain is detected by thewear measurement device. The dialable pin configuration, in conjunctionwith a chain wear measurement device or system, may thus be used tocontrol the wear of the wear surfaces of the pin and chain links tomaintain the chain at a desired working configuration, without having toreplace the center link each time that the pin is rotated.

Also, the dialable pin configuration of the present invention may thusprovide significantly greater life cycles for such chains and pins,since the pins do not have to be replaced when one or more of the pinswears a sufficient amount. Such a pin-head and side link design may beimplemented with a pin with a ball member or the like or a pin with agenerally cylindrical shaft portion and no ball member, withoutaffecting the scope of the present invention. Also, such a dialable pinconcept is suitable for use on a double headed pin or a single headed orbolted pin, with the head or heads of the pin being lobed ornon-circular shaped or formed and engaged with a correspondingly formedrecess in one of the side links, while a threaded end of a bolted pinmay extend through a circular opening in the other side link and may besecured therein by a nut or other fastener, without affecting the scopeof the present invention. Also, by providing a rotationallynon-symmetrical or non-uniform wear surface on the shaft portion or ballmember, the pin may accommodate wear or erosion or deterioration ordegradation of the wear surface of the center link when the pin isrotated or dialed to provide the next wear surface of the shaft or ballmember. The wear surfaces and degree of wear may be monitored by a wearmeasurement device or system to further control the wear of the chain.

The ball members and/or the concave surfaces of the center links of thepresent invention may comprise a metallic material, or may comprise anylon or plastic or polymeric material, without affecting the scope ofthe present invention. The selected material is preferably a highlydurable material which may minimize wear of the ball and/or the concavesurface when the chain is in use and moving through various curves whileunder load.

Therefore, the present invention provides a bolted or pinned orhalf-bolted chain which has improved flexibility to ease negotiation ofthe chain links through sharp vertical changes in the chain path. Theball members of the present invention allow for pivotable movementbetween the center link and side links as the chain negotiates throughthe conveying path. More particularly, the ball member allows the centerlink to pivot about a longitudinal axis of the bolt, stud or pin in aconventional manner, while also allowing the center link to pivot aboutthe ball member in other directions as well, such as pivoting upward ordownward relative to the side links. The ball member and bolt or studcombination of the present invention thus allows the bolted chain tonegotiate inclines along the conveying path without binding or excessivewear occurring at the chain joints. Also, the ball and socket typeconnection of the present invention allows the chain to flex about bothaxes, which further may allow the chain to twist or corkscrew over asufficient length of track. Because the ball member may be loosely fitonto the bolt or stud, the ball member of the present invention providesfor an easy assembly process of the bolt or stud and also facilitateseasy disassembly or disconnection of the chain links for service ormaintenance of the bolted chain. The present invention thus provides fora chain with much greater flexibility which is easy to manufacture andassemble.

Referring now to FIGS. 33 and 34, a chain or section of chain 710includes a pair of side links 712 a, 712 b and a center link 714. Thecenter link 714 is retained between the side links 712 a, 712 b by a pin716, such as an I-pin or other type of pin, bolt, stud or the like,which extends through a center region or opening 714 a of center link714 and through an opening 713 a in each side link 712 a, 712 b. Pin 716is retained in and through side links 712 a, 712 b by opposite headportions 716 a of pin 716 engaging a recessed region 713 b of arespective side link 712 a, 712 b. Pin 716 includes a generallyspherical or toroidal-shaped ball member 720 which is molded around ashaft portion 716 b of pin 716. Chain 710 includes multiple linkagesconnected together in a continuous loop about a conveying system, as isknown in the art. For ease of description, only one set of linkages ofthe chain is shown and described herein, with the other linkages beingsubstantially identical.

Shaft portion 716 b of pin 716 may comprise a metallic material, and mayprovide a substantially smooth exterior surface. The shaft portion 716 bmay be coated or treated, or may have a material deposited thereon, in amanner to provide a low coefficient of friction surface of the shaftportion. For example, the shaft portion may be treated with a TEFLON®coating or type material or a hard, carbon or diamond like material, orany other durable and low coefficient of friction material or slickmaterial, without affecting the scope of the present invention. The lowcoefficient of friction or slick surface facilitates the breaking freeof the molded sleeve or ball 720 (as discussed below) and furtherfacilitates rotation or movement of the sleeve or ball 720 relative tothe shaft of the pin as the chain negotiates through its conveying path.Although shown as an I-pin type fastener or connector, the side links712 a, 712 b and center 714 may be retained together via any other typeof pin or bolt or stud for connecting the links of a chain, withoutaffecting the scope of the present invention.

Each head portion 716 a of pin 716 may comprise a generally rectangularshaped head such that portions of the head 716 a extend laterallyoutward from the end of the shaft portion 716 b in opposite directions.Each side link 712 a, 712 b includes a pair of slotted openings 713 awhich may be sized to receive head 716 a therethrough when the head isrotated approximately 90 degrees from the orientation shown in FIGS. 33and 34, in order to facilitate assembly and disassembly of the chainlinks. Each side link 712 a, 712 b includes a recessed region or pocket713 b at each end for head 716 a of pin 716 to rest when the chain isassembled. The recessed region 713 b is defined by a raised end portion713 c and raised inward portions 713 d which engage the sides of thehead 716 a to substantially preclude rotation of the pin 716 relative toside links 712 a, 712 b and center link 714.

Center link 714 may comprise a generally oval shaped or elongated ringdefining inner opening 714 a. Center link 714 includes an inner roundedor concave surface 714 b (FIGS. 33 and 34) at each end thereof forengaging and partially receiving ball member 720 therein to retaincenter link 714 at ball member 720 as the chain is moved along theconveying path. Optionally, concave surface 714 b may be coated ortreated with a low coefficient of friction material, similar to shaftportion 716 b of pin 716 discussed above, to reduce the function betweenball member 720 and center link 714.

Ball member 720 may comprise a plastic or polymeric member which ismolded onto the substantially smooth metallic shaft portion 716 b of pin716. Ball member 720 is molded around the shaft portion 716 b after pin716 is formed and is then allowed to cool and harden around the shaftportion. Because shaft portion 716 b has a substantially smooth, andpreferably slick, outer surface, ball member 720 may be twisted, slid,or otherwise moved relative to shaft portion 716 b to break ball member720 free from shaft member 716 b. Ball member 720 may then be freelyrotatable and movable around and along shaft portion 716 b to allow forrelative movement between ball member 720 and pin 716. Ball member 716thus provides a unitarily formed ball which is movable relative to pin716 and center link 714. Ball member 716 may include one or more spacersor sleeve portions extending from one or both ends of the ball member,such as discussed above, to assist in retaining the ball member in placealong the shaft portion.

Ball member 720 may be formed by injection molding a polymeric materialaround the shaft portion 716 b of pin 716 or may be formed via any othermolding process or method, without affecting the scope of the presentinvention. Ball member 720 may be formed of a durable, hard polymericmaterial, such as a nylon material or filled nylon material, a PBTmaterial, or an engineering plastic or the like. Clearly, however, othermaterials may be used for ball member 720, without affecting the scopeof the present invention.

Optionally, ball member 720 may provide an exterior surface which has adurable and low coefficient of friction to also enhance the relativemovement between ball member 720 and center link 714. Optionally, ballmember 720 may be coated with a slick or low coefficient of frictionmaterial, similar to shaft portion 716 b discussed above, to furtherreduce the friction between the components, without affecting the scopeof the present invention.

Ball member 720 thus allows for pivotal movement of center link 714 viasliding engagement between ball member 720 and shaft portion 716 b ofpin 716 and/or sliding engagement between concave surface 714 b and ballmember 720. This provides greater flexibility to chain 710 and may allowchain 710 to negotiate sharper vertical curves in the conveying pathwithout binding the links or joints of the chain. The ball member andcorrespondingly formed concave surface thus may distribute the loadsover a generally constant surface area, reducing or substantiallyeliminating the stress concentration that typically occur whenconventional chains articulate through vertical inclines and declines.The ball member and concave surface engagement may also function todistribute the loads between the chain links and pin over a greatersurface area than conventional chains. This decreases the wear on thepins and chain links and may result in less maintenance and a greaterlife cycle for the chain. Also, because chain 710 may provide a lowcoefficient of friction surface at shaft 716 b of pin 716 and/or atcenter link 714, ball member 720 may provide for a reduced amount offriction between the center link 714 and pin 716, which may furtherreduce wear on the components and may result in even less maintenanceand an even greater life cycle of the chain.

Referring now to FIG. 35, a chain or section of chain 710′ includes sidelinks 712 a, 712 b and a center link 714, which are retained together bya pin 716′. Side links 712 a, 712 b and center link 714 may besubstantially similar to the side links and center link discussed abovewith respect to chain 710, such that a detailed discussion of thesecomponents will not be repeated herein.

Pin 716′ includes head portions 716 a′, similar to pin 716, and a shaftportion 716 b′ extending between the opposite head portions 716 a′.Shaft portion 716 b′ comprises a generally cylindrical shaft portion andincludes a notched or narrowed section 716 c′ at a central regionthereof. Notched section 716 c′ of pin 716′ may extend circumferentiallyaround shaft portion 716 b′, so as to define a narrowed diameter centralregion of shaft portion 716 b′. However, notched section 716 c′ mayoptionally provide separate notched portions or indents or grooves in aportion of the central region of the shaft portion, without affectingthe scope of the present invention.

Similar to pin 716, discussed above, shaft portion 716 b′ and notchedsection 716 c′ of pin 716′ may provide substantially smooth, cylindricalexterior surfaces. Shaft portion 716 b′ may be coated or treated in amanner to provide a low coefficient of friction surface of the shaftportion, such as described above with respect to pin 716 of chain 710.The low coefficient of friction or slick surface facilitates thebreaking free of a molded sleeve or ball 720′ (discussed below) andfurther facilitates rotation or movement of the sleeve or ball 720′relative to the shaft of the pin as the chain negotiates through itsconveying path. Although shown as an I-pin type fastener or connector,the links 712 a, 712 b and 714 may be retained together via any othertype of pin or bolt or stud, such as formed using the principlesdescribed above, for connecting the links of a chain, without affectingthe scope of the present invention.

Pin 716′ includes a generally spherical or toroidal-shaped ball member720′ around shaft portion 716 b′ of pin 716′. Ball member 720′ maycomprise a plastic or polymeric member which is molded onto thesubstantially smooth shaft portion 716 b′ of pin 716′, such that aninner portion of ball member 720′ is molded within notched section 716c′ of pin 716′. Ball member 720′ is molded around the shaft portion 716b′ after pin 716′ is formed and is then allowed to cool and hardenaround the shaft portion. Because shaft portion 716 b′ and notchedsection 716 c′ may have a substantially smooth and cylindrical outersurface, and which may be treated with a slick material or coating, ballmember 720′ may be twisted or otherwise moved relative to shaft portion716 b′ to break ball member 720′ free from shaft member 716 b′. Ballmember 720′ may then be freely rotatable around and notched section 716c′ of shaft portion 716 b′ to allow for relative movement between ballmember 720′ and pin 716′. Notched section 716 c′ functions to retainball member 720′ in place and limits or substantially precludeslongitudinal movement of ball member 720′ along shaft portion 716 b′ ofpin 716′.

Similar to ball member 720, ball member 720′ may be formed by injectionmolding a polymeric material around the shaft portion 716 b′ of pin 716′or may be formed via any other molding process or method, withoutaffecting the scope of the present invention. Optionally, ball member720′ may provide an exterior surface which is durable and which may havea low coefficient of friction to enhance the relative movement betweenball member 720′ and center link 714. Optionally, ball member 720′ maybe coated with a slick or low coefficient of friction material, such asdiscussed above with respect to ball member 720, to further reduce thefriction between the components. As discussed above, concave surface 714b of center link 714 may also or otherwise be coated or treated toprovide a surface having a lower coefficient of friction for engagementwith ball member 720′.

Referring now to FIG. 36, a chain or section of chain 810 includes sidelinks 712 a, 712 b and a center link 714, which are retained together bya pin 816. Side links 712 a, 712 b and center link 714 may besubstantially similar to the side links and center link discussed abovewith respect to chain 710, such that a detailed discussion of thesecomponents will not be repeated herein.

Pin 816 includes opposite head portions 816 a, similar to pin 716, and ashaft portion 816 b extending between the opposite head portions 816 a.Shaft portion 816 comprises a generally cylindrical shaft portion andincludes a spherical or toroidal-shaped ball member 820 integrallyformed at a generally central region thereof. Similar to pin 716,discussed above, shaft portion 816 b and ball member 820 of pin 816 mayprovide a substantially smooth exterior surface. Shaft portion 816 b andball member 820 may be coated or treated in a manner to provide a lowcoefficient of friction surface, such as described above with respect topin 716 of chain 710. The low coefficient of friction or slick surfacefacilitates the breaking free of a molded sleeve 817 (discussed below)from the shaft portion and ball member of pin 816 and furtherfacilitates rotation or movement of the sleeve relative to the shaft andball of the pin as the chain negotiates through its conveying path.Although shown as an I-pin type fastener or connector, the links 712 a,712 b and 714 may be retained together via any other type of pin or boltor stud for connecting the links of a chain, such as formed using theprinciples discussed above, without affecting the scope of the presentinvention.

Pin 816 includes a polymeric or plastic sleeve portion 817 molded aroundshaft portion 816 b and ball member 820. The slick surface of the shaftportion 816 b and ball member 820 allows sleeve portion 817 to be brokenfree from shaft portion 816 b after sleeve portion 817 is moldedthereon, and allows for rotation of sleeve portion 817 about shaftportion 816 b and ball member 820. Optionally, sleeve portion 817 mayprovide a highly durable and slick or low friction surface forengagement of sleeve 817 with the concave surface 714 b of center link714. As can be seen in FIG. 36, sleeve portion 817 may extend alongshaft portion 816 b to head portions 816 a, such that sleeve portion 817also provides a highly durable and optionally slick or low frictionsurface for engagement between shaft portion 816 b and the end walls 713e of openings 713 a of side links 712 a, 712 b.

Similar to ball members 720 and 720′, sleeve portion 817 may be moldedover shaft portion 816 b after pin 816 has been formed. Because shaftportion 816 b and ball member 820 of pin 816 provide a substantiallysmooth surface and may have a treated slick surface at which sleeveportion 817 is molded, the sleeve portion may be twisted or otherwisemoved relative to pin 816 to break the molded sleeve portion away fromshaft portion 816 b and ball member 820, such that sleeve portion 817may be generally freely rotatable about shaft portion 816 b and ballmember 820. When chain 810 is assembled, sleeve portion 817 may thus bemovable relative to side links 712 a, 712 b, center link 714 and pin 816as the chain flexes or bends through its conveying path.

Similar to ball member 720, sleeve portion 817 may be formed byinjection molding a polymeric material around the shaft portion 816 band ball member 820 of pin 816 or may be formed via any other moldingprocess or method, without affecting the scope of the present invention.Optionally, sleeve portion 817 may provide an exterior surface (or maybe treated with a material or coating) which has a low coefficient offriction to enhance the relative movement between sleeve portion 817 andcenter link 714, such as discussed above with respect to ball member720. As discussed above, concave surface 714 b of center link 714 mayalso or otherwise be coated or treated to provide a surface having alower coefficient of friction for engagement with sleeve portion 817.

Referring now to FIG. 37, a chain or section of chain 810′ includes sidelinks 712 a, 712 b and a center link 714′, which are retained togetherby a pin 816′. Side links 712 a, 712 b and center link 714∝0 may besubstantially similar to the side links and center link discussed abovewith respect to chain 710, such that a detailed discussion of thesecomponents will not be repeated herein. However, center link 714′ ofchain 810′ may have a generally straight or slightly curved pin engagingsurface 714 b′ at its ends, and does not include a concave pin engagingsurface.

Pin 816′ includes opposite head portions 816 a′, similar to pin 716, anda shaft portion 816 b′ extending between the opposite head portions 816a′. Shaft portion 816′ comprises a generally cylindrical shaft andpreferably provides a substantially smooth exterior surface. Shaftportion 816 b′ may be coated or treated in a manner to provide a lowcoefficient of friction surface of the shaft portion, such as describedabove with respect to pin 716 of chain 710. For example, the shaftportion may be treated with a TEFLON® coating or type material or ahard, diamond like material or any other low coefficient of frictionmaterial or slick material, without affecting the scope of the presentinvention, to substantially reduce the friction between the components.The low coefficient of friction or slick surface facilitates thebreaking free of a molded sleeve 817′ and further facilitates rotationor movement of the sleeve relative to the shaft of the pin as the chainnegotiates through its conveying path. Although shown as an I-pin typefastener or connector, the links 712 a, 712 b and 714′ may be retainedtogether via any other type of pin or bolt or stud for connecting thelinks of a chain, such as formed using the principles discussed above,without affecting the scope of the present invention.

Pin 816′ includes a polymeric or plastic sleeve portion 817′ moldedaround shaft portion 816 b′. Optionally, sleeve portion 817′ may providea highly durable and slick or low friction surface for engagement ofsleeve portion 817′ with the surface or end 714 b′ of center link 714′.As can be seen in FIG. 37, sleeve portion 817′ may extend along shaftportion 816 b′ to head portions 816 a′, such that sleeve portion 817′may also provide a highly durable (and optionally a slick or lowfriction surface) for engagement of shaft portion 816 b′ with the endwalls 713 e of openings 713 a of side links 712 a, 712 b. As discussedabove, the end of center link 714′ may also or otherwise be coated ortreated to provide a surface having a lower coefficient of friction forengagement between sleeve portion 817′ and center link 714′.

Similar to ball members 720 and 720′ and sleeve portion 817, sleeveportion 817′ is molded over shaft portion 816 b′ after pin 816′ has beenformed. Because shaft portion 816 b′ of pin 816′ provides asubstantially smooth and slick surface at which sleeve portion 817′ ismolded, the sleeve portion may be twisted or otherwise moved relative topin 816′ to break the sleeve portion away from shaft portion 816 b′,such that sleeve portion 817′ may be generally freely rotatable aboutshaft portion 816 b′. When chain 810′ is assembled, sleeve portion 817′is movable relative to side links 712 a, 712 b, center link 714′ and pin816′ as the chain flexes or bends through its conveying path. Similar toball member 720, sleeve portion 817′ may be formed by injection moldinga polymeric material around the shaft portion 816 b′ of pin 816′ or maybe formed via any other molding process or method, without affecting thescope of the present invention.

As shown in FIG. 38, a chain or section of chain 910 may include a pin916 and side links (not shown) and a center link 914. Center link 914includes a plastic or polymeric insert or member 915 at each end forengagement with the shaft portion 916 b of pin 916. The plastic insert915 may be coated or treated with or may otherwise provide a durable andslick or low friction material surface for engagement between plasticinsert 915 of center link 914 and pin 916. Insert 915 may be molded atan end 914 b of center link 914, such as via an injection moldingprocess or the like. However, insert 915 may be molded to center link914 via other molding means, or may be snapped or removably mounted oraffixed to center link 914, without affecting the scope of the presentinvention.

Pin 916 includes opposite head portions 916 a and shaft portion 916 bextending between the opposite head portions 916 a. Shaft portion 916may comprise a generally cylindrical shaft and may provide asubstantially smooth exterior surface. Similar to pin 716, shaft portion916 may be coated or treated in a manner to provide a slick or lowcoefficient of friction surface. However, other pins, bolts, studs orthe like may be implemented with chain 910, without affecting the scopeof the present invention.

Each end 914 b of center link 914 provides a recessed area 914 c, suchthat insert 915 may be molded or retained generally within recessed area914 c and may be substantially fixed or non-movable within recessed area914 c. In the illustrated embodiment, recessed area 914 c provides apair of raised end stops 914 d at opposite ends of a generallyoctagonal, curved surface 914 e. The octagonal surface 914 e and endstops 914 d function to substantially preclude movement of insert 915relative to center link 914 after insert 915 has been molded thereto.Although shown as an octagonal shaped surface, clearly, other shapes maybe provided at recessed area 914 c to limit or substantially precludemovement of insert 915 relative to center link 914.

Insert 915 may provide a durable and low coefficient of friction surface915 a for engagement with shaft portion 916 b of pin 916. The lowcoefficient of friction surface may provide enhanced relative movementbetween pin 916 and center link 914, which may reduce wear on the centerlink and pin as the chain negotiates through the conveying path. Insert915 may be made from a durable polymeric or plastic material, such as anylon material, such as a filled nylon material, a PBT material, or anengineering plastic or the like. Optionally, the insert 915 and/or theshaft portion 916 b of pin 916 may be treated or coated with a materialwhich provides a low coefficient of friction to enhance relativemovement between the pin and the center link and to reduce the wear onthe components to increase the life cycle of the chain.

Although shown as being implemented with a cylindrical shaft pin, it isenvisioned that an insert in accordance with the present invention mayinclude a concave surface (not shown in FIG. 38), such as a surfacesimilar to concave surface 714 b of center link 714, discussed above,for engagement with a ball member or other sleeve or the like (also notshown in FIG. 38) on the shaft portion of the pin, such as a ball memberor sleeves of the types discussed above or the like. The insert may beremovably mounted or affixed to the center link to facilitate removaland replacement of the insert to provide a center link with areplaceable wear surface.

Referring now to FIG. 39, a chain or section of chain 910′ includes apin 916′, side links 912′ and a center link 914′. Center link 914′includes a plastic or polymeric insert or member 915′ at each end forengagement with the shaft portion 916 b′ of pin 916′. The plastic insert915′ may be coated or treated with or may otherwise provide a durableand slick or low friction material surface for engagement between centerlink 914′ and pin 916′. Insert 915′ may be molded at an end 914 b′ ofcenter link 914′, such as via an injection molding process or the like.However, insert 915′ may be molded to center link 914′ via other moldingmeans, without affecting the scope of the present invention. Optionally,insert 915′ may be a replaceable insert which may be snapped orotherwise affixed to the end 914 b′ of the center link 914′. Insert 915′may include a concave engagement surface or socket 915 a′ for generallyuniformly engaging an outer surface of a ball portion or member 920′ ofpin 916′, discussed below.

Pin 916′ includes opposite head portions 916 a′ and shaft portion 916 b′extending between the opposite head portions 916 a′. Shaft portion 916′comprises a generally cylindrical shaft and includes generally sphericalball member or portion 920′ at a generally central portion of shaftportion 916 b′. Ball member 920′ may be formed as part of the shaft ofpin 916′ or may be slid or molded or formed onto pin 916′, such asutilizing the principles discussed above or the like. The outer surfaceof shaft portion 916 b′ and ball portion 920′ preferably provides asubstantially smooth exterior surface for engagement with insert 915′ atcenter link 914′. Similar to pin 716, shaft portion 916 b′ and ballportion 920′ of pin 916′ may be coated or treated in a manner to providea slick or low coefficient of friction surface. However, other pins,bolts, studs or the like may be implemented with chain 910′, withoutaffecting the scope of the present invention.

Similar to center link 914, discussed above, each end 914 b′ of centerlink 914′ may provide a recessed area (shown generally at 914 c′), suchthat insert 915′ may be molded generally within the recessed area andmay be substantially fixed or non-movable within the recessed area.Recessed area 914 c′ may be generally similar to recessed area 914 cdiscussed above, such that a detailed discussion of the recessed areawill not be repeated herein. Recessed area 914 c′ of center link 914′may include a concave mating surface or socket, which generallycorresponds to the curvature of socket or surface 915 a′ of insert 915′.The insert 915′ may then be molded to have a generally uniform thicknessat the socket area. However, the center link 914′ may have a generallyflat or otherwise formed mating surface for the insert 915′, withoutaffecting the scope of the present invention.

Insert 915′ may provide a durable and low coefficient of frictionsurface 915 a′ for engagement with ball member or portion 920′ of pin916′. The low coefficient of friction may provide enhanced relativemovement between pin 916′ and center link 914′, which may reduce wear onthe center link and pin as the chain negotiates through the conveyingpath. The corresponding shapes or curvature of the surface 915 a′ andball member 920′ provides for enhanced flexibility of chain 910′, withreduced wear on the ends of center link 914′ and/or on the shaft of pin916′. Insert 915′ may be made from a durable polymeric or plasticmaterial, such as a nylon material, such as a filled nylon material, aPBT material, or an engineering plastic or the like. The ball and socketarrangement minimizes any tension and shear stresses on the insert 915′,such that insert 915′ may be exposed primarily to compression loads,which are less damaging to the plastic insert. Optionally, the insert915′ and/or the ball portion 920′ of pin 916′ may be treated or coatedwith a material which provides a low coefficient of friction to enhancerelative movement between the pin and the center link and to reduce thewear on the components to increase the life cycle of the chain.

Optionally, as shown in FIG. 40, a chain or section of chain 910″ mayinclude a pin 916″, side links 912″ and a center link 914″. Center link914″ includes a plastic or polymeric insert or member 915″ at each endfor engagement with the shaft portion 916 b″ of pin 916″. The plasticinsert 915″ may be coated or treated with or may otherwise provide adurable and slick or low friction material surface for engagementbetween center link 914″ and pin 916″. Insert 915″ may be molded at anend 914 b″ of center link 914″, such as via an injection molding processor the like. However, insert 915″ may be molded to center link 914″ viaother molding means, without affecting the scope of the presentinvention. Insert 915″ may include a convex engagement surface 915 a″for generally uniformly engaging a narrowed, outer surface of shaftportion 916 b″ of pin 916″, as discussed below.

Pin 916″ includes opposite head portions 916 a″ and shaft portion 916 b″extending between the opposite head portions 916 a″. Shaft portion 916″comprises a generally cylindrical shaft and includes a narrowed portion916 c″ at a generally central portion of shaft portion 916 b″. Narrowedportion 916 c″ provides an inwardly curved surface for generally uniformengagement with the outwardly curved surface 915 a″ of insert 915″. Theouter curved surface 916 c″ of shaft portion 916 b″ may provide asubstantially smooth exterior surface for engagement with convex surface915 a″ of insert 915″ at center link 914″. Similar to pin 716, shaftportion 916″ may be coated or treated in a manner to provide a slick orlow coefficient of friction surface. However, other pins, bolts, studsor the like may be implemented with chain 910″, without affecting thescope of the present invention.

Center link 914″ may be substantially similar to center links 914, 914′,discussed above, such that a detailed discussion of the center link 914″will not be repeated herein. Suffice it to say that insert 915″ may bemolded generally within a recessed area at each end of center link 914″and may be substantially fixed or non-movable within the recessed area.Optionally, the insert may be snapped or otherwise affixed to orremovably mounted to the center link and may provide a removable andreplaceable wear surface for the center link.

Similar to inserts 915 and 915′, insert 915″ may provide a durable andlow coefficient of friction surface 915 a″ for engagement with thenarrowed curved portion 916 c″ of shaft 916 b″ of pin 916″. The lowcoefficient of friction provides enhances relative movement between pin916″ and center link 914″, which may reduce wear on the center link andpin as the chain negotiates through the conveying path. Thecorresponding shapes or curvature of the outwardly curved surface 915 a″of insert 915″ and the inwardly curved surface 916 c″ of pin 916″provides for enhanced flexibility of chain 910″, with reduced wear onthe ends of center link 914″ and/or on the shaft of pin 916″. Insert915″ may be made from a durable polymeric or plastic material, such as anylon material, such as a filled nylon material, a PBT material, or anengineering plastic or the like. Optionally, the insert 915″ and/or thecurved surface 916 c″ of pin 916″ may be treated or coated with amaterial which provides a low coefficient of friction surface or coatingto enhance relative movement between the pin and the center link and toreduce the wear on the components to increase the life cycle of thechain.

Although each of the embodiments of chain sections discussed above withrespect to FIGS. 33-40 includes a pin with oval or rectangular headportions, it is further envisioned that a round-headed pin may beprovided (such as with any of the chains of the present inventiondiscussed above) with a rounded head at each end of the pin and a ballmember and/or sleeve or the like on the shaft portion between the heads.The head portions may then insert through enlarged, generally circularopenings in the side links and may slide outwardly toward the ends ofthe side links to a narrowed opening. The narrowed opening substantiallyprecludes the circular heads from moving therethrough, and thus retainsthe side links relative to the center links and the pin. The side linksinclude a recessed area around the narrowed opening to receive therounded head therein to substantially preclude movement of the pinrelative to the side links toward the enlarged openings in the sidelinks. The pin is thus allowed to rotate relative to the side links andthe center link, while allowing greater flexibility and/or reduced wearof the chain.

Although shown as being joined by a pin in FIGS. 33-40, it is furtherenvisioned that the linkages of the chains of the present invention mayotherwise be joined by other pins, bolts, studs, half-bolt / half-pintype pins or fasteners, or any other fastening or joining means forretaining the side links and the center links together. The fastening orjoining means may be formed using the principles discussed above.

It is envisioned that any of the pin and chain link embodimentsdiscussed above may have wear surface components comprising any suitablematerial. For example, the wear surface components may comprise steel orother metallic material, bronze or other softer metallic material, apolymeric material, such as engineering plastics or other strong anddurable polymeric material, a ceramic material, a sintered material, aTEFLON® coating or material, a fluorocarbon material or the like. It isalso envisioned that any of the pin and chain link embodiments discussedabove may include a low coefficient of friction or slick coating at oron the wear surfaces of the pins and/or chain links. The coating thusmay provide enhanced relative movement or rotation or sliding betweenthe wear surfaces to enhance performance of the section of chain and toincrease the life cycle of the section of chain. The coating maycomprise a TEFLON® type coating or a diamond like coating or the like orany other low coefficient of friction or slick coating or the likesuitable for such an application.

The present invention thus may provide a diamond like coating (DLC) overa metallic or plastic (or other material) wear surface of the pin orchain link. The wear surface component may define a substantially smoothwear surface to enhance sliding or moving engagement with acorresponding wear surface of the section of chain. The metallic wearsurface component or components may be formed to be substantially smoothvia any known means, such as via tumbling, vibrating or the like of thecomponent, such as tumbling with ceramic chips or steel chips or thelike, while the plastic wear surface component or components may bemolded to the desired form and/or tumbled or vibrated to achieve thedesired surface smoothness, without affecting the scope of the presentinvention.

The diamond like coating on the wear surface or surfaces providesenhanced performance and an increased life cycle to the section ofchain. Because such a diamond like coating may be sensitive to pointloading and shock in some applications, the wear surface components ofthe present invention may comprise a ball member and a correspondinglyformed socket to reduce or substantially eliminate such point loadingconditions. Such ball and socket arrangements reduce such shock orimpact or point loading concerns by spreading out the contact area overa wider area.

Therefore, the present invention provides a sleeve and/or a ball memberand a pin or bolt or stud which allows for pivotal movement of thecenter link via sliding engagement of the center link along the ballmember and via sliding engagement of the sleeve or ball member aroundthe shaft of the pin. This provides greater flexibility to the chain andmay allow the chain to negotiate sharper vertical curves in theconveying path without binding the links or joints of the chain. Theball member and correspondingly formed concave surface thus maydistribute the loads over a generally constant surface area, reducing orsubstantially eliminating the stress concentration that typically occurwhen conventional chains articulate through vertical inclines anddeclines. The ball member and concave surface engagement may alsofunction to distribute the loads between the chain links and pin or boltor stud over a greater surface area than conventional chains. Thisdecreases the wear on the pin and chain links and may result in lessmaintenance and a greater life cycle for the chain.

The ball member, and/or the sleeve over the ball member or shaft of thepin, and/or the insert at the center link may comprise a high strength,durable polymeric or plastic material. The selected material maycomprise a highly durable material which may minimize wear of the ballmember and/or the concave surface when the chain is in use and movingthrough various curves while under load. The material may be selected ortreated or coated to also provide a low coefficient of friction surfaceto enhance movability of the components relative to one another and toreduce wear on the components. Optionally, one or more of the contactingsurfaces may be treated or coated with a material which may provide alow coefficient of friction surface between the contacting components tofurther reduce wear on the chain. The ball member, sleeve, insert orother wear surface component may optionally comprise a metallicmaterial, such as steel or the like or bronze or other softer metallicor the like, and may be coated or treated to enhance the low frictionengagement between respective wear surfaces. Because the ball member,pin and/or center link of the present invention may include a lowfriction surface, the present invention provides for a reduced amount offriction between the center link and the pin and/or between the sidelinks and the pin, which further reduces wear on the components and mayresult in less maintenance and a greater life cycle of the chain. It isenvisioned that the low friction surfaces of the present invention maysubstantially reduce or obviate the need for lubrication of the jointsof the chain during use. The present invention thus may provide anon-lubricated chain with plastic components.

The present invention also provide for a unitary plastic componentformed or molded onto a pin to enhance the performance of the chain. Themolded ball member or sleeve may be broken free from the pin to allowrelative movement between the pin and the ball member or sleeve whilealso allowing relative movement between the ball or sleeve and the chainlinks. The molded ball or sleeve is thus a unitarily formed, durablemember which provides an engagement component between the metalcomponents of the chain. Optionally, a metal or plastic ball or sleevemay be slid or pressed onto a stud or bolt type pin and may be removabletherefrom.

The present invention thus provides a chain which has improvedflexibility to ease negotiation of the chain links through sharpvertical changes in the chain path. The ball member or the narrowedshaft portion of the present invention allows for pivotable movementbetween the center link and side links as the chain negotiates throughthe conveying path. More particularly, the ball member or narrowed shaftportion allows the center link to pivot about a longitudinal axis of thepin in a conventional manner, while also allowing the center link topivot relative to the pin, such as about the ball member or within thecurved shaft portion, in other directions as well, such as pivotingupward or downward relative to the side links. The ball member/curvedengagement surface and pin combination of the present invention thusallows the chain to negotiate inclines along the conveying path withoutbinding or excessive wear occurring at the chain joints. Also, the balland socket type connection of the present invention allows the chain toflex about both axes, which further may allow the chain to twist orcorkscrew over a sufficient length of track. The present invention thusprovides for a chain with much greater flexibility and greater lifecycles which is easy to manufacture and assemble.

Changes and modifications in the specifically described embodiments maybe carried out without departing from the principles of the presentinvention, which is intended to be limited only by the scope of theappended claims, as interpreted in accordance with the principles ofpatent law.

1. A conveying system for conveying product along a conveying path, saidconveying system comprising: a track element; a plurality of trolleysmovable along said track element; a chain connecting to said trolleysfor moving said trolleys along said track element; wherein said chaincomprises a plurality of chain sections having a pin that connects arespective center chain link with a respective pair of side chain links,each of said center chain links having a pin engaging surface at an endthereof; wherein said pin of a respective chain section extends throughsaid side chain links and said center chain link and connects said sidechain links and said center chain link with said center chain link beingdisposed at least partially between said side chain links, said pincomprising opposite end portions and a shaft portion extending betweensaid opposite end portions, wherein said shaft portion comprises first,second and third wear surfaces for selective engagement with said pinengaging surface of said center chain link; and wherein said pin isselectively adjustable to first, second and third positions relative tosaid chain links to generally align a respective one of said first,second and third wear surfaces with said pin engaging surface of saidcenter chain link, said pin being generally non-rotatable relative to atleast one of said side chain links when in each of said first, secondand third positions.
 2. The conveying system of claim 1 furthercomprising a chain wear measurement device operable to detect at least aportion of said chain and to determine a degree of wear in said chain assaid chain moves along said conveying path, said pin being selectivelyadjustable to a selected one of said first, second and third positionsin response to an output of said wear measurement device.
 3. Theconveying system of claim 1, wherein said shaft portion comprises agenerally cylindrical shaped shaft portion, and wherein said first,second and third wear surfaces comprise respective portions of saidgenerally cylindrical shaft portion.
 4. The conveying system of claim 1,wherein said first wear surface has a first radius of curvature and saidsecond wear surface has a second radius of curvature, said second radiusof curvature being greater than said first radius of curvature so thatsaid second wear surface, when engaged with said pin engaging surface,accommodates for wear of said pin engaging surface that occurs duringoperation of said section of chain when said first wear surface isengaged with said pin engaging surface.
 5. The conveying system of claim1, wherein at least one of said end portions comprises a head portionhaving at least one lobe extending radially outwardly therefrom andradially outwardly relative to said shaft portion for engaging areceiving portion of a respective one of said side chain links to limitrotation of said pin relative to said respective side chain link whensaid pin is in a selected one of said first, second and third positions.6. The conveying system of claim 1, wherein said shaft portion isrotationally non-uniform, said first wear surface having a differentradius than said second and third wear surfaces and said second wearsurface having a different radius than said third wear surface.
 7. Theconveying system of claim 1, wherein said pin includes indiciaindicative of which of said first, second and third wear surfaces isgenerally aligned with said pin engaging surface.
 8. The conveyingsystem of claim 1, wherein one of said end portions of said pincomprises a threaded portion for engaging a fastener.
 9. A method ofadjusting a pin of a section of chain to adjust a wear surface of saidpin relative to a pin engaging surface of a center link of said sectionof chain, said method comprising: providing a conveying system forconveying product along a conveying path, said conveying systemcomprising a track element, a plurality of trolleys movable along saidtrack element, and a chain having a plurality of sections of chainjoined together and connected to said trolleys for moving said trolleysalong said track element; wherein at least some of said sections ofchain comprise a center chain link and two side chain links and a pinconnecting said center chain link to said side chain links via insertionof said pin through said chain links, said pin comprising opposite endportions and a shaft portion extending between said opposite endportions, said shaft portion having first and second wear surfaces thatselectively engage a pin engaging surface of said center chain Link, atleast one of said end portions of said pin being non-rotatablypositionable at least one of said side chain links when said pin is in aselected one of first and second positions; non-rotatably positioningsaid pin in said first position, said first wear surface being generallyaligned with said pin engaging surface of said center chain link whensaid pin is in said first position; wearing said first wear surface viarelative movement of said first wear surface and said pin engagingsurface while said chain conveys product along said conveying pathduring operation of said conveying system; and selectively rotating saidpin and non-rotatably positioning said pin in said second position, saidsecond wear surface being generally aligned with said pin engagingsurface of said center chain link when said pin is in said secondposition.
 10. The method of claim 9 including determining a degree ofwear of said chain, wherein selectively rotating said pin comprisesselectively rotating said pin in response to the determination of thedegree of wear of said chain.
 11. The method of claim 9, whereinproviding a conveying system comprises providing a conveying systemhaving at least some of said sections of chain comprising a pin withsaid shaft portion of said pin comprising a rotationally non-uniformshaft portion defining said first and second wear surfaces, wherein saidsecond wear surface comprises at least one of (a) a larger radius thansaid first wear surface and (b) a larger radius of curvature than saidfirst wear surface.
 12. The method of claim 9 including providingindicia at said pin indicative of which of said first and second wearsurfaces is generally aligned with said pin engaging surface.